Đề thi thử ACT (Enhanced) số 1: ACT Mock Test 1

English (35 phút)

Passage I: The Bees Above the Library

In the passage, each underlined portion carries a small number. For each question, choose the best alternative for the underlined portion. If you think the original version is best, choose NO CHANGE. Some questions ask about a section of the passage or the passage as a whole; a bracketed number alone, like [5], marks a point in the passage.

When Mara Lindqvist first proposed keeping bees on the roof of the public library, the board members looks at her as if she had suggested raising goats in the reading room. Bees, they argued, would sting patrons, clog the gutters, and frighten the children who came for story hour. One member also asked who would pay if a visitor turned out to be allergic. Mara, a retired science teacher, had expected this reaction. She came to the next meeting prepared to argue.

The research showed that honeybees forage up to three miles from their hive and can visit thousands of flowers in a single day. The honey came from a friend's rooftop colony across the river. The invitation was to visit that colony in person. Three board members accepted, and they're doubts faded once they saw the bees working calmly among the flower boxes. A month later, the board voted five to two to approve the project.

The library installed two hives the following spring. Mara trained a small group of volunteers, most of them teenagers who had never been closer to a bee than the picture on a cereal box. They learned to light the smoker, lift the frames slowly, and recognizing the pale, waxy cells where the queen had laid her eggs. By the end of the first season, several of them could spot a sick hive faster than Mara could.

However, the project has grown far beyond two hives. The library now hosts a monthly honey tasting, and the children's room displays an observation hive behind thick glass, where visitors can watch the bees dance; a movement that tells other bees where to find nectar. Last summer the volunteers harvested ninety pounds of honey, which they sold at the farmers' market to buy new equipment. In all that time, not a single patron has reported a sting.

Mara still keeps the folder of research on her desk, though she rarely needs it now. When new board members ask about the bees, she simply explains that bees are important pollinators.

1. Underlined portion 1: "looks"
   • NO CHANGE
   • looked
   • have looked
   • look
2. Underlined portion 2: "She came to the next meeting prepared to argue." Which choice most effectively sets up the information that follows in the next paragraph?
   • NO CHANGE
   • She decided to bring her concerns to the next meeting.
   • She had taught biology for thirty years.
   • She came to the next meeting with a folder of research, a jar of honey, and an invitation.
3. Underlined portion 3: "can visit thousands of flowers in a single day." Which choice provides the most relevant support for Mara's view that the bees would not harm library patrons?
   • NO CHANGE
   • have been kept by humans for thousands of years.
   • rarely sting unless their colony is threatened.
   • produce more honey in warm climates.
4. Underlined portion 4: "they're"
   • NO CHANGE
   • there
   • its
   • their
5. Underlined portion 5: " who had never been closer to a bee than the picture on a cereal box" The writer is considering deleting the underlined portion, so that the sentence ends with the word "teenagers." Should the underlined portion be kept or deleted?
   • Kept, because it explains why Mara chose teenagers rather than adults as volunteers.
   • Kept, because it adds a humorous detail that shows how unfamiliar the volunteers were with bees.
   • Deleted, because it repeats information given in the first paragraph.
   • Deleted, because it contradicts the statement that the volunteers were trained.
6. Underlined portion 6: "recognizing"
   • NO CHANGE
   • recognized
   • to have recognized
   • recognize
7. Underlined portion 7: "However,"
   • NO CHANGE
   • Since then,
   • Nevertheless,
   • In contrast,
8. Underlined portion 8: "dance; a movement that"
   • NO CHANGE
   • dance. A movement that
   • dance a movement that
   • dance, a movement that
9. Underlined portion 9: "which they sold at the farmers' market"
   • NO CHANGE
   • which, they sold at the farmers' market,
   • which they sold, at the farmers' market,
   • and which they sold at the farmers' market
10. Underlined portion 10: "explains that bees are important pollinators." Which choice most effectively concludes the essay by suggesting that the project's success now speaks for itself?
    • NO CHANGE
    • hands them a jar of honey.
    • gives a long speech about safety.
    • asks them to vote again.

Passage II: The Language of Wheels

In the passage, each underlined portion carries a small number. For each question, choose the best alternative for the underlined portion. If you think the original version is best, choose NO CHANGE. Some questions ask about a section of the passage or the passage as a whole; a bracketed number alone, like [15], marks a point in the passage.

For forty-one years, my grandfather repaired bicycles in a narrow shop on Tran Hung Dao Street. He never put up a sign. Customers found him the way water finds a crack: by following the paths of those who had come before them.

The summer I turned fifteen, my parents sent me to help him. I expected to sweep floors and fetch tools. Instead, on my first morning, he hands me a wheel with a bent rim and said, "Listen to it." I spun the wheel and heard nothing but a faint, uneven whisper. He spun it again and pointed at the spot where the rim brushed the brake pad. That brushing was the whisper, a sound so soft that I had mistaken it for the wind.

Over the following weeks, I learned that every bicycle tell a story about its rider. A chain coated in red dust belonged to someone who rode the unpaved roads near the river. Brake pads worn thin on only one side meaning that the rider braked hard with one hand, usually because the other hand was busy holding an umbrella. My grandfather read these signs quickly, carefully, and with great speed, the way a doctor reads an X-ray. The shop had a tin roof that grew hot by noon.

Late in August, a woman brought in a rusted bicycle that had belonged to her father. She wanted it to run again, not for riding but for remembering. My grandfather and I spent three days on it, we replaced the chain, straightened the frame, and polished the handlebars until they shone. When she came to collect it, she rang the bell twice and laughed, and then she left.

I am in college now, studying mechanical engineering. My professors talk about tolerances and torque, and I find the lectures difficult.

1. Underlined portion 1: "crack: by following"
   • NO CHANGE
   • crack; by following
   • crack. By following
   • crack by, following
2. Underlined portion 2: "hands"
   • NO CHANGE
   • handed
   • has handed
   • will hand
3. Underlined portion 3: ", a sound so soft that I had mistaken it for the wind" The writer is considering deleting the underlined portion, so that the sentence ends with the word "whisper." Should the underlined portion be kept or deleted?
   • Kept, because it explains how the grandfather first learned to repair bicycles.
   • Kept, because it shows how faint the sound was and why the narrator had not noticed it.
   • Deleted, because it shifts the focus of the paragraph to the weather.
   • Deleted, because it contradicts the statement that the narrator heard a whisper.
4. Underlined portion 4: "tell"
   • NO CHANGE
   • were telling
   • told
   • have told
5. Underlined portion 5: "meaning"
   • NO CHANGE
   • meant
   • to mean
   • having meant
6. Underlined portion 6: "quickly, carefully, and with great speed,"
   • NO CHANGE
   • with speed and quickly,
   • quickly and carefully,
   • quickly, carefully, and fast,
7. Underlined portion 7: "The shop had a tin roof that grew hot by noon." The writer is considering deleting this sentence. Should the sentence be kept or deleted?
   • Kept, because it explains why the grandfather worked so quickly.
   • Kept, because it describes the setting in which the narrator learned to read bicycles.
   • Deleted, because it does not relate to the paragraph's focus on what bicycles revealed about their riders.
   • Deleted, because it contradicts the earlier description of the shop as narrow.
8. Underlined portion 8: "spent three days on it, we replaced"
   • NO CHANGE
   • spent three days on it we replaced
   • spent three days on it. We replaced
   • spending three days on it, we replaced
9. Underlined portion 9: "and then she left." Which choice best connects the woman's reaction to her reason for having the bicycle repaired?
   • NO CHANGE
   • and paid at the counter.
   • because the bell was louder than a new one.
   • because the bell sounded exactly as it had when she was a child.
10. Underlined portion 10: "and I find the lectures difficult." Which choice most effectively concludes the essay by connecting the narrator's present to the lesson of the first morning in the shop?
    • NO CHANGE
    • and I take careful notes in every class.
    • and I nod, but part of me is still listening for a wheel's faint whisper.
    • and I hope to open a shop of my own someday.

Passage III: The Box That Changed Trade

In the passage, each underlined portion carries a small number. For each question, choose the best alternative for the underlined portion. If you think the original version is best, choose NO CHANGE. Some questions ask about a section of the passage or the passage as a whole; a bracketed number alone, like [25], marks a point in the passage.

Before the 1950s, loading a cargo ship was slow, exhausting work. Dockworkers carried sacks, barrels, and crates up gangplanks one at a time, and a single ship could sit in port for a week while it's cargo was stowed. Goods were often damaged or stolen along the way. For shipowners, the days spent tied up at the dock were often more expensive than the days at sea.

Malcom McLean, a trucking businessman from North Carolina, often waited for hours, for many long hours, at ports while the loads from his trucks were moved, piece by piece, onto ships. He wondered why the entire trailer box could not simply be lifted off its wheels and placing on deck. McLean, who had started his trucking company with a single used truck, decided to find out for himself.

In April 1956, McLean tested the idea. A converted tanker named the Ideal X carried fifty-eight metal boxes from Newark, New Jersey, to Houston, Texas. At the time, the voyage drew little attention. Few people noticed the figure that mattered most: loading the Ideal X had cost about sixteen cents a ton, compared with nearly six dollars a ton for loose cargo. Yet within two decades, the steel container had transformed global trade.

The secret was standardization. Once shipping companies agreed on common sizes, a container could travel from a factory to a truck, a train, and a ship without nobody opening it. Cranes, designed for the purpose could load a ship in hours instead of days. Because handling costs fell so sharply, containers were painted in bright colors. Today, most of the manufactured goods that cross the oceans travel inside such boxes.

Containers come in several sizes. Many dockworkers lost their jobs as machines replaced the crews who had once carried cargo by hand, and some port cities declined as trade moved to newer, larger harbors. In New York, for example, much of the shipping business left the old piers of Manhattan and Brooklyn for new container terminals across the harbor in New Jersey. The box had made the world smaller, but not everyone was better off for it.

1. Underlined portion 1: "exhausting work. Dockworkers carried"
   • NO CHANGE
   • exhausting work, dockworkers carried
   • exhausting work dockworkers carried
   • exhausting, work. Dockworkers carried
2. Underlined portion 2: "it's cargo was"
   • NO CHANGE
   • its cargo was
   • its' cargo was
   • it's cargo were
3. Underlined portion 3: "often waited for hours, for many long hours,"
   • NO CHANGE
   • waited often for many hours of time
   • often waited for hours long
   • often waited for hours
4. Underlined portion 4: "placing"
   • NO CHANGE
   • placed
   • to place
   • having placed
5. At point [25], the writer is considering adding the following sentence: "A tanker is a ship built to carry liquids such as oil." Should the writer make this addition?
   • Yes, because it explains why the Ideal X could carry only fifty-eight boxes.
   • Yes, because it helps the reader understand McLean's background in trucking.
   • No, because it adds a definition that distracts from the account of the test voyage.
   • No, because it contradicts the statement that the Ideal X had been converted.
6. Underlined portion 6: "without nobody opening it."
   • NO CHANGE
   • without anybody opening it.
   • without nobody to open it.
   • with nobody not opening it.
7. Underlined portion 7: "Cranes, designed for the purpose"
   • NO CHANGE
   • Cranes designed, for the purpose
   • Cranes designing for the purpose
   • Cranes designed for the purpose
8. Underlined portion 8: "containers were painted in bright colors." Which choice most clearly describes an economic consequence of the falling handling costs?
   • NO CHANGE
   • McLean bought more trucks.
   • the Ideal X was retired.
   • companies could profitably make goods in one country and sell them on the other side of the world.
9. Underlined portion 9: "Containers come in several sizes." Which choice provides the most effective transition from the preceding paragraph to this one?
   • NO CHANGE
   • Many ships today are very large.
   • The new efficiency, however, came at a price for some.
   • Trucks also carry containers.
10. Suppose the writer's goal had been to write an essay explaining how a single innovation reshaped an industry. Would this essay accomplish that goal?
    • Yes, because it traces how the shipping container cut loading time and costs and changed where goods were made.
    • Yes, because it focuses mainly on the dockworkers who lost their jobs.
    • No, because it describes only one voyage, the trip of the Ideal X.
    • No, because it is mostly a biography of Malcom McLean.

Passage IV: Water Bears

In the passage, each underlined portion carries a small number. For each question, choose the best alternative for the underlined portion. If you think the original version is best, choose NO CHANGE. Some questions ask about a section of the passage or the passage as a whole; a bracketed number alone, like [35], marks a point in the passage.

In a clump of damp moss on almost any garden wall, there lives thousands of animals that most people have never seen. A single drop of water squeezed from the moss may hold dozens of them. Tardigrades, also called water bears, are about half a millimeter long and can be studied in a laboratory. Under a microscope, they look like plump, wrinkled bears wearing a costume that is too large for them. More than a thousand species have been named, and new ones are described every year.

What makes tardigrades famous, however, is not their appearance and their toughness. When their surroundings dry out, a tardigrade pulls in its legs and loses almost all of its water. Shriveled and dry, scientists call the resulting ball a tun. In this state, the animal's metabolism slows to a tiny fraction of its normal rate. A tun can survive for years. When water returns, the animal swells, stretches, and walks away as though nothing had happened.

Scientists have tested these limits in dramatic ways. They have frozen tuns, heated them, and squeezed them under pressures far greater than any found in the deepest ocean. In 2007, tardigrades were carried into orbit aboard a satellite, they were exposed to the vacuum of space. Some survived and later produced healthy offspring. A few even survived the sun's unfiltered ultraviolet light, which is deadly to most living things. Researchers have also found that certain species make special proteins that form a glassy shield inside their cells as they dry, protecting delicate structures from damage.

Tardigrades also live in the deep ocean. Vaccines and some medicines must be kept cold, which makes them difficult to deliver to remote places. A single power cut on the way can ruin a whole shipment. If scientists can learn how tardigrades preserve their cells, they might someday design medicines that can be stored dry at room temperature. The tiny animals in the garden moss may one day help keep people healthy around the world.

1. Underlined portion 1: "there lives thousands of"
   • NO CHANGE
   • there live thousands of
   • there lives thousand of
   • their live thousands of
2. Underlined portion 2: "can be studied in a laboratory." Which choice provides details that best prepare the reader for the comparison in the next sentence?
   • NO CHANGE
   • are found on every continent.
   • waddle on eight stubby legs, each tipped with tiny claws.
   • were first described more than two centuries ago.
3. Underlined portion 3: "a costume that is too large for them."
   • NO CHANGE
   • a costume that is too large for it.
   • costumes that is too large for them.
   • a costume, that is too large, for them.
4. Underlined portion 4: "and"
   • NO CHANGE
   • but
   • or
   • nor
5. Underlined portion 5: "Shriveled and dry, scientists call the resulting ball a tun."
   • NO CHANGE
   • Shriveled and dry, the resulting ball is what scientists call a tun.
   • Scientists, shriveled and dry, call the resulting ball a tun.
   • Shriveled and dry, a tun is called by scientists the resulting ball.
6. Underlined portion 6: "as though nothing had happened."
   • NO CHANGE
   • as though nothing happening.
   • like nothing was happening to it.
   • as if nothing had been happening to it before.
7. Underlined portion 7: "aboard a satellite, they were exposed"
   • NO CHANGE
   • aboard a satellite they were exposed
   • aboard a satellite, they, were exposed
   • aboard a satellite, where they were exposed
8. Underlined portion 8: "Researchers have also found that certain species make special proteins that form a glassy shield inside their cells as they dry, protecting delicate structures from damage." The writer is considering deleting this sentence. Should the sentence be kept or deleted?
   • Kept, because it describes a survival mechanism that the final paragraph suggests could have practical uses.
   • Kept, because it explains how the tardigrades were carried into orbit.
   • Deleted, because it repeats the description of the tun in the second paragraph.
   • Deleted, because it is unrelated to tardigrades' ability to survive.
9. Underlined portion 9: "Tardigrades also live in the deep ocean." Which choice most effectively introduces the final paragraph?
   • NO CHANGE
   • Moss grows best in shady places.
   • These discoveries may prove useful far outside the laboratory.
   • Some tardigrades are larger than others.
10. Underlined portion 10: "how tardigrades preserve their cells, they might"
    • NO CHANGE
    • how tardigrades preserve their cells they might
    • how tardigrades preserve, their cells, they might
    • how, tardigrades preserve their cells, they might

Passage V: The Lantern Makers

In the passage, each underlined portion carries a small number. For each question, choose the best alternative for the underlined portion. If you think the original version is best, choose NO CHANGE. Some questions ask about a section of the passage or the passage as a whole; a bracketed number alone, like [45], marks a point in the passage.

On the evening of each full moon, the old town of Hoi An, in central Vietnam, dims its streetlights, and the narrow lanes glow, instead with thousands of silk lanterns. Their light ripples across the Thu Bon River, where small boats carry visitors past the old merchant houses. Visitors often assume that the lanterns are made in a factory. In fact, most of them are made by hand in small family workshops a few streets from the river. The tradition is often traced to the Chinese and Japanese merchants who settled in the port centuries ago.

The process begins with bamboo. A craftsperson splits a length of bamboo into thin, flexible ribs, then soaking them so that they can be bent without cracking. The ribs are lashed together into a frame, which may be round, oval, or shaped like a diamond. Next, silk is stretched over the frame and glued in place, a step that demands steady hands, because a single wrinkle can spoil the lantern's shape. Finally, the lantern is left to dry, and a painter may add a border of flowers or a line of poetry.

Many people make lanterns in Hoi An. His workshop produces about forty lanterns on a good day and fewer when the air is humid, since the glue dries slowly then. Each of his apprentices spend their first months doing nothing but splitting bamboo. Only after a year are they trusted to stretch the silk.

In recent years, cheaper lanterns made of nylon have appeared in tourist shops. They cost less than half as much as silk ones, but they fade quickly in the sun. Some workshops have responded by offering classes, which are held on weekends. Most students leave with a lopsided lantern, sore fingers, and a new respect for the craft. For Mr. Thanh, the classes are worth the effort. "When people make one lantern themselves," he says, "they never look at a lantern the same way again."

1. Underlined portion 1: "glow, instead with"
   • NO CHANGE
   • glow instead, with
   • glow instead with
   • glow; instead with
2. Underlined portion 2: "Visitors often assume that the lanterns are made in a factory. In fact, most of them are made by hand" Which choice most effectively combines the underlined sentences?
   • Visitors often assume, that the lanterns are made in a factory, in fact, most of them are made by hand
   • Visitors, assuming that the lanterns are made in a factory, most of them are made by hand
   • Although visitors often assume that the lanterns are made in a factory, and most of them are made by hand
   • Visitors often assume that the lanterns come from a factory, but most of them are made by hand
3. Underlined portion 3: "soaking"
   • NO CHANGE
   • soaks
   • soaked
   • to soak
4. Underlined portion 4: "place, a step"
   • NO CHANGE
   • place. A step
   • place; a step
   • place a step
5. Underlined portion 5: "Many people make lanterns in Hoi An." Which choice most effectively introduces the person whose workshop and views are described in the rest of the essay?
   • NO CHANGE
   • Lanterns are also sold online.
   • Mr. Thanh, who has made lanterns for more than thirty years, says that the hardest skill to teach is patience.
   • Some lanterns are taller than a person.
6. Underlined portion 6: "since"
   • NO CHANGE
   • although
   • unless
   • whereas
7. Underlined portion 7: "Each of his apprentices spend their first months"
   • NO CHANGE
   • Each of his apprentices spends the first months
   • Each of his apprentices have spent their first months
   • All of his apprentice spends the first months
8. Underlined portion 8: "have appeared"
   • NO CHANGE
   • has appeared
   • appearing
   • was appearing
9. Underlined portion 9: "which are held on weekends." Which choice best explains how the classes respond to the competition from nylon lanterns?
   • NO CHANGE
   • which are taught in two languages.
   • which last about two hours.
   • in which visitors build a small lantern of their own and learn why silk lanterns last longer.
10. The writer wants to add the following sentence to the essay: "Bamboo grows quickly in the hills near Hoi An, so the material is cheap and easy to find." The sentence would most logically be placed:
    • at the end of the first paragraph.
    • at the beginning of the second paragraph, before the sentence "The process begins with bamboo."
    • in the second paragraph, directly after the sentence "The process begins with bamboo."
    • at the end of the essay.

Math (50 phút)

Mathematics

Solve each problem and choose the correct answer. You may use a calculator. Unless otherwise stated, figures are not necessarily drawn to scale, the word line means a straight line, and the word average means arithmetic mean.

1. A jacket is on sale for $24.00 after a 20% discount. What was the original price of the jacket?
   • $19.20
   • $28.80
   • $30.00
   • $31.20
2. What is the value of 3x² - 2x + 5 when x = -2?
   • 11
   • 13
   • 17
   • 21
3. What value of x satisfies the equation 5(x - 3) = 2x + 9?
   • 8
   • 12
   • 16
   • 24
4. The mean of 5 test scores is 82. Four of the scores are 78, 85, 90, and 74. What is the fifth score?
   • 78
   • 81.75
   • 82
   • 83
5. What is the slope of the line that passes through the points (2, -1) and (6, 7) in the standard (x,y) coordinate plane?
   • 1/2
   • 2
   • 4
   • 8
6. Which of the following is equivalent to (2x³y)(-3xy⁴)?
   • -6x⁴y⁵
   • -6x³y⁴
   • -x⁴y⁵
   • 6x⁴y⁵
7. A bag contains 4 red marbles, 6 blue marbles, and 5 green marbles. One marble is chosen at random. What is the probability that the marble is NOT blue?
   • 1/3
   • 2/5
   • 3/5
   • 2/3
8. A rectangle has a perimeter of 46 centimeters and a length of 15 centimeters. What is the area of the rectangle, in square centimeters?
   • 92
   • 120
   • 180
   • 225
9. Which of the following is a factored form of x² - 5x - 14?
   • (x + 7)(x - 2)
   • (x - 7)(x + 2)
   • (x - 14)(x + 1)
   • (x - 2)(x - 7)
10. If f(x) = 2x² - 3, what is the value of f(-3)?
    • 3
    • 9
    • 15
    • 33
11. What is the distance between the points (1, 2) and (7, 10) in the standard (x,y) coordinate plane?
    • 10
    • 12
    • 14
    • 100
12. A car travels 225 miles in 3 hours 45 minutes. What is the car's average speed, in miles per hour?
    • 56.25
    • 60
    • 62.5
    • 75
13. If x + y = 10 and x - y = 4, what is the value of xy?
    • 21
    • 24
    • 28
    • 40
14. Which of the following describes all solutions of the inequality -3x + 7 > 19?
    • x < 4
    • x > 4
    • x > -4
    • x < -4
15. In right triangle ABC, angle C is the right angle, AC = 12, and BC = 9. What is sin A?
    • 3/5
    • 4/5
    • 3/4
    • 4/3
16. The ratio of boys to girls in a class of 40 students is 3:5. How many girls are in the class?
    • 15
    • 24
    • 25
    • 30
17. The price of a ticket rose from $80 to $100. By what percent did the price increase?
    • 20%
    • 25%
    • 80%
    • 125%
18. A circle has a circumference of 10π inches. What is the area of the circle, in square inches?
    • 10π
    • 20π
    • 25π
    • 100π
19. What is the value of (3²)³ · 3⁻⁴?
    • 3
    • 9
    • 27
    • 81
20. What is the sum of the solutions of the equation x² - 6x + 8 = 0?
    • -6
    • 2
    • 4
    • 6
21. Which of the following is an equation of the line that passes through (4, 3) and is perpendicular to the line y = 2x + 1?
    • y = 2x - 5
    • y = (1/2)x + 1
    • y = -(1/2)x + 1
    • y = -(1/2)x + 5
22. What is the median of the data set 7, 3, 9, 12, 5, 8?
    • 7
    • 7.5
    • 8
    • 8.5
23. What are all the solutions of the equation |2x - 5| = 9?
    • x = 7 or x = -2
    • x = 7 or x = 2
    • x = -7 or x = 2
    • x = 7 only
24. The first term of an arithmetic sequence is 4, and the common difference is 6. What is the 20th term?
    • 110
    • 114
    • 118
    • 124
25. The first three terms of a geometric sequence are 3, 6, and 12. What is the 8th term?
    • 96
    • 192
    • 288
    • 384
26. If f(x) = x + 3 and g(x) = x², what is the value of f(g(2))?
    • 7
    • 10
    • 25
    • 49
27. Angle θ is an acute angle in a right triangle, and tan θ = 5/12. What is cos θ?
    • 5/13
    • 5/12
    • 12/13
    • 13/12
28. A cylinder has a radius of 3 meters and a height of 8 meters. What is the volume of the cylinder, in cubic meters?
    • 12π
    • 24π
    • 48π
    • 72π
29. Which of the following is equal to (3 + 2i)(1 - i), where i² = -1?
    • 1 - i
    • 3 - 2i
    • 5 + i
    • 5 - i
30. If log₃ x = 4, what is the value of x?
    • 7
    • 12
    • 64
    • 81
31. A fair coin is tossed and a fair six-sided die is rolled. What is the probability of getting heads on the coin and a 6 on the die?
    • 1/12
    • 1/8
    • 1/6
    • 2/3
32. A code consists of 2 letters (A through Z) followed by 3 digits (0 through 9). Letters and digits may repeat. How many different codes are possible?
    • 6,760
    • 67,600
    • 676,000
    • 17,576,000
33. A theater sold 50 tickets for a total of $460. Adult tickets cost $12 each, and child tickets cost $7 each. How many adult tickets were sold?
    • 22
    • 25
    • 28
    • 30
34. What is the vertex of the parabola y = x² - 8x + 11?
    • (-4, -5)
    • (4, -5)
    • (4, 11)
    • (8, 11)
35. Which of the following gives the center and radius of the circle (x - 2)² + (y + 3)² = 16?
    • Center (-2, 3), radius 4
    • Center (2, -3), radius 4
    • Center (2, -3), radius 16
    • Center (-2, 3), radius 16
36. A garden is 12 feet wide and 15 feet long. What is the area of the garden in square yards? (1 yard = 3 feet)
    • 20
    • 27
    • 60
    • 180
37. For all x ≠ -2 and x ≠ -3, which of the following is equivalent to (x² - 9)/(x² + 5x + 6)?
    • (x + 3)/(x + 2)
    • (x - 3)/(x + 3)
    • (x - 3)/(x + 2)
    • -3/2
38. A 20-foot ladder leans against a vertical wall and makes a 60° angle with the level ground. How high up the wall does the top of the ladder reach, in feet?
    • 10
    • 10√2
    • 10√3
    • 20
39. Which of the following data sets has the greatest standard deviation?
    • 10, 10, 10, 10
    • 2, 6, 14, 18
    • 8, 9, 11, 12
    • 9, 10, 10, 11
40. In a game, a player wins $10 with probability 0.2, wins $2 with probability 0.3, and wins nothing otherwise. What is the expected amount a player wins per game?
    • $2.60
    • $4.00
    • $6.00
    • $12.00
41. A survey of 100 students found the following: of the 50 students in Grade 11, 30 play a sport and 20 do not; of the 50 students in Grade 12, 25 play a sport and 25 do not. If a student who plays a sport is chosen at random, what is the probability that the student is in Grade 12?
    • 1/4
    • 5/11
    • 1/2
    • 5/9
42. A town has a population of 2,000. The population grows by 5% each year. What will the population be after 2 years?
    • 2,100
    • 2,200
    • 2,205
    • 2,210
43. If sin θ = 0.6 and 90° < θ < 180°, what is cos θ?
    • -0.8
    • -0.6
    • 0.4
    • 0.8
44. A circle has a radius of 9 centimeters. What is the length of an arc of the circle intercepted by a central angle of 120°, in centimeters?
    • 3π
    • 6π
    • 9π
    • 12π
45. If f(x) = 3x - 6, what is the value of f⁻¹(9)?
    • -1
    • 1
    • 3
    • 5

Reading (40 phút)

Passage I: Literary Narrative

Read the passage and choose the best answer to each question. Refer to the passage as often as necessary. This passage is from an original short story, "The Tuner."

The house on Calle Ortega had a gate that no longer closed, and Inés noticed that her uncle did not bother to try it. He walked straight up the cracked path with his leather case swinging at his side, the way he walked into every house, as though he had been expected for years.

Inés had been expected for exactly one week. Her mother had arranged it: a summer job, three afternoons a week, carrying her uncle's tools and writing down what he told her to write down. "He needs someone who can read his handwriting," her mother had said, "and you need something to do besides stare at your phone." Inés had not argued, mostly because she had assumed the job would last a few days before her uncle grew tired of her.

So far he had not grown tired of her, but he had not said much to her either. Tomás Aguilar had tuned pianos in the city for thirty-four years. He talked to pianos more than he talked to people. In the car he hummed single notes, testing them against some standard only he could hear, and when Inés asked a question he would answer it two or three minutes later, as if the question had needed time to travel.

The woman who opened the door was older than Inés had expected, small and very straight, with a cardigan buttoned to the throat despite the heat. "Señora Valdés," her uncle said, and bowed slightly, which Inés had never seen him do.

The piano stood in a room that smelled of lemon polish and closed windows. It was an upright with a dark walnut case, and the lid over the keys was shut. Señora Valdés did not open it. She stood beside it with one hand resting on the top, the way someone might rest a hand on the shoulder of a friend.

"It has not been played in nine years," she said. "Not since my husband died. But I have it tuned every spring."

Inés looked at her uncle, expecting him to say something about how a piano that is never played does not really need tuning. He said nothing of the kind. He opened his case, laid out his tuning hammer and his rubber mutes in a neat row on a towel, and lifted the lid.

For the next hour Inés sat on a hard chair and wrote numbers in the notebook while he called them out. The work was slower than she had imagined. He would strike a key, listen, turn the pin a fraction, strike again, and listen longer. Sometimes he struck the same key a dozen times. Once he stopped completely and sat with his head tilted, and Inés realized he was listening not to the piano but to the faint hum of a refrigerator in the next room, waiting for it to switch off.

Señora Valdés did not leave. She sat in an armchair near the window with her hands folded, and Inés slowly understood that this was not politeness. The woman was listening, too. Each time a note slid from slightly sour to clean, something in her face eased, as if a small knot had been loosened.

When he had finished, her uncle did not close the lid right away. He played a scale, slowly, from the bottom of the keyboard to the top. Then, to Inés's surprise, he played the opening of a piece she did not know, something quiet that moved in small steps, and stopped after only a few measures.

Señora Valdés had closed her eyes. "That one," she said. "He used to play that one on Sunday mornings."

"I know," her uncle said. "I tuned it for him."

In the car afterward, Inés waited. She had learned by now that if she asked a question, the answer would come eventually, but this time she did not even know what to ask. Finally she said, "You don't charge her the full price. I saw the receipt."

Her uncle hummed a note, then another. Three blocks went by. "A piano that sits in a closed room still goes out of tune," he said at last. "The wood moves. The strings stretch. Nobody hears it happening, but it happens anyway." He glanced at her. "She needs to know that it is still being cared for. That is what she pays me for."

Inés wrote nothing in the notebook. She thought she would remember it without writing it down.

1. The point of view from which the passage is told is best described as that of:
   • a narrator who closely follows Inés's observations and her gradually changing understanding.
   • Inés, looking back on the summer as an adult many years later.
   • Tomás, who explains the details of his work to his niece.
   • Señora Valdés, who remembers her husband's music.
2. According to the passage, Inés did not argue with her mother's plan mainly because she:
   • wanted to learn how to tune pianos herself.
   • admired her uncle and wanted to spend time with him.
   • expected her uncle to grow tired of her within a few days.
   • needed to earn money during the summer.
3. The detail that Tomás answers questions "two or three minutes later" mainly serves to:
   • suggest that he is annoyed by Inés's questions.
   • characterize him as a man absorbed in his own thoughts and in sound.
   • show that he has difficulty hearing people speak.
   • indicate that the car was too noisy for conversation.
4. The narrator's remark that Tomás bowed slightly, "which Inés had never seen him do," most strongly suggests that Tomás:
   • is uncomfortable meeting strangers.
   • was trying to impress Inés.
   • was meeting Señora Valdés for the first time.
   • feels unusual respect for Señora Valdés.
5. The comparison of Señora Valdés's hand on the piano to a hand "on the shoulder of a friend" suggests that she:
   • intends to sell the piano soon.
   • feels a personal, affectionate connection to the piano.
   • is too tired to stand without support.
   • wants to prevent Tomás from opening the lid.
6. The episode in which Tomás waits for the refrigerator to switch off primarily illustrates:
   • how closely Tomás listens while he works.
   • how old and poorly maintained the house is.
   • that Inés is growing bored with the job.
   • that Señora Valdés is impatient for him to finish.
7. As it is used in the passage, the word "sour" most nearly means:
   • bitter-tasting.
   • bad-tempered.
   • out of tune.
   • spoiled.
8. It can most reasonably be inferred that Tomás plays the opening of the quiet piece because he:
   • wants to show Inés how skilled he is.
   • is testing whether the highest notes are in tune.
   • has just learned the piece and wants to practice it.
   • knows that Señora Valdés's husband used to play it.
9. Tomás's explanation at the end of the passage suggests that Señora Valdés pays for the tuning mainly because:
   • she plans to begin playing the piano again.
   • it reassures her that the piano, and what it represents, is still being cared for.
   • a piano that is not tuned will be damaged beyond repair.
   • her husband asked her to have it tuned every spring.

Passage II: Social Science

Read the passage and choose the best answer to each question. Refer to the passage as often as necessary. This passage discusses the idea of the third place.

In 1989 the sociologist Ray Oldenburg gave a name to something most people had experienced without describing. In his book The Great Good Place, he argued that a healthy life needs three kinds of settings. The first place is the home. The second is the workplace or school. The third place is everything else that people visit by choice and without obligation: the corner café, the barbershop, the public library, the park bench where the same retirees gather each morning to argue about football.

Third places, in Oldenburg's account, share several features. They are cheap or free to enter. They are close enough to home that people can walk or ride there without planning. They have regulars, people whose familiar faces make a newcomer feel that the place has a life of its own. Above all, they are places where conversation is the main activity. Nobody is required to be there, and nobody is in charge of anyone else, so people of different ages, jobs, and incomes meet on roughly equal terms.

Oldenburg believed that such places were disappearing from many American towns, and he blamed the design of the suburbs. When houses are separated from shops by wide roads and long distances, every errand requires a car, and a trip to a café becomes an outing rather than a habit. Zoning rules that kept homes and businesses apart, he argued, had removed the small, walkable gathering spots where neighbors once ran into each other.

Later researchers have tested parts of this argument. Studies of neighborhoods in several countries have found that people who live within a short walk of shops, cafés, and parks tend to know more of their neighbors by name and report greater trust in them. Such findings do not prove that the walkable places cause the trust. People who enjoy socializing may simply choose to live in lively neighborhoods. Still, the pattern has been strong enough to persuade many city planners that the physical layout of a neighborhood shapes how its residents relate to one another.

The internet has complicated Oldenburg's picture. Some observers argue that online forums and multiplayer games function as third places, since they offer regulars, conversation, and a sense of belonging without a fixed address. Others point out that most online spaces lack one of Oldenburg's key features: they sort people by interest. A café draws whoever happens to live nearby, including people one would never seek out. An online forum about a single hobby draws only people who already share that hobby. The chance encounter with someone unlike oneself, which Oldenburg considered one of the third place's chief gifts, is far less likely.

Public libraries offer an interesting test case. Over the past few decades, many libraries have redesigned themselves less as warehouses for books and more as community rooms. They host language classes, homework clubs, job fairs, and knitting circles. They provide free internet access and a warm, safe place to sit for people who have nowhere else to go during the day. In this sense they fit Oldenburg's definition well: they are free, open to all, and close to home. Yet they also differ from his ideal in one respect. Libraries are traditionally quiet places, and Oldenburg insisted that lively conversation was the heart of a third place. Many libraries have responded by creating separate zones, keeping silent reading rooms while allowing noise in cafés, maker spaces, and meeting rooms.

Critics have raised a different concern about the third place idea. Oldenburg wrote warmly of taverns and coffee shops, but these are businesses that must sell something. As rents rise in popular neighborhoods, a café may begin to discourage customers who linger over a single cup for hours, the very regulars who give a third place its character. A space that depends on spending, these critics argue, cannot be fully open to everyone. For this reason some planners argue that the most reliable third places are public ones, such as parks, plazas, and libraries, that are paid for by taxes rather than by purchases.

Whatever form they take, third places seem to answer a need that neither home nor work can fully satisfy. At home people are family members; at work they are employees or students. In a third place they can simply be neighbors, and that modest role, Oldenburg suggested, is one on which a community depends.

1. The main purpose of the passage is to:
   • argue that cafés are the best kind of third place.
   • describe the history of zoning laws in American suburbs.
   • explain the idea of the third place and consider how later evidence and changes bear on it.
   • show that online forums have replaced public libraries.
2. According to the passage, Oldenburg blamed the loss of third places mainly on:
   • suburban design that separated homes from shops and other businesses.
   • the rise of the internet and online games.
   • rising rents in popular neighborhoods.
   • a decline in public funding for libraries.
3. The passage indicates that studies of walkable neighborhoods:
   • proved that living near cafés causes people to trust their neighbors.
   • found no connection between walkability and neighborly trust.
   • were carried out only in American suburbs.
   • found a link between walkability and trust but did not show that one causes the other.
4. The sentence "People who enjoy socializing may simply choose to live in lively neighborhoods" (paragraph 4) serves mainly to:
   • support Oldenburg's claim about the suburbs.
   • offer an alternative explanation for a research finding.
   • introduce the discussion of online spaces.
   • describe the residents of a particular neighborhood.
5. According to the passage, some observers believe that online spaces differ from Oldenburg's third places because online spaces:
   • have no regular visitors.
   • do not allow conversation.
   • tend to gather people who already share an interest.
   • cost too much to join.
6. Based on the passage, in what way do public libraries differ from Oldenburg's ideal third place?
   • They charge fees for most of their services.
   • They are usually located far from people's homes.
   • They are open only to students and job seekers.
   • They have traditionally expected quiet rather than conversation.
7. As it is used in paragraph 7, the word "linger" most nearly means:
   • stay for a long time.
   • wait in a line.
   • complain loudly.
   • pay slowly.
8. The critics mentioned in paragraph 7 would most likely agree with which of the following statements?
   • Cafés are more welcoming than public parks.
   • A place that requires customers to buy something cannot be completely open to all.
   • Oldenburg was wrong to say that third places need regulars.
   • Libraries should be replaced by coffee shops.
9. The final paragraph suggests that, in a third place, people:
   • take on the same roles they have at work.
   • meet mainly with members of their own families.
   • relate to one another as neighbors rather than through family or work roles.
   • are expected to spend money to belong.

Passage III: Humanities

Read the passage and choose the best answer to each question. Refer to the passage as often as necessary. Passage A and Passage B are each written by a translator of poetry. Some questions refer to one passage, and some refer to both.

Passage A

When I began translating poems, I believed my first duty was to the poet's words. If the original said "river," I wrote "river," even when "stream" might sound better in English. A translator who changes the words, I reasoned, is no longer translating but writing a new poem and signing someone else's name to it.

I still hold much of that belief. Readers who cannot read the original language trust the translator to show them what the poet actually said. When a translation drifts too far, readers form opinions about a poet based on choices the poet never made. I have seen reviewers praise a foreign poet for a striking image that, in the original, was entirely ordinary; the translator had invented it. Such praise is a small injustice to the poet and a larger one to the reader.

Fidelity also protects the translator from vanity. It is tempting to improve a poem, to sharpen a dull line or brighten a plain adjective, and every such improvement feels at the moment like a gift to the reader. But the reader did not ask for my poem. The reader asked for the poet's.

Yet strict fidelity has costs I did not see at first. Many poems depend on sound: rhyme, rhythm, the echo of one vowel against another. These effects rarely survive a word-by-word crossing. A line that sings in the original can arrive in English as flat as a shopping list. A reader of such a translation learns what the poem says but not why anyone loved it.

My compromise has been to keep the poet's images and statements as close as I can, and to accept the loss of the music. Where the loss is great, I add a short note explaining what the original sounds like. Notes are not elegant, and some readers find them distracting. But a note is honest. It tells the reader plainly what has been lost, instead of covering the gap with something the translator made up.

Passage B

A poem is not a message that happens to be written in lines. It is an event that happens to a reader: a quickening of the pulse at a turn of phrase, a laugh at an unexpected rhyme, a silence after the last word. When I translate, I am trying to make that event happen again, for a reader who does not know the original language. The words are my materials, not my master.

This means I sometimes change what the poet literally said. If a poem uses a pun that cannot exist in English, I look for a different pun that does the same work at the same moment. If the original rhymes, my version rhymes, even if the rhyme forces me to replace a "river" with a "stream" or a "stream" with a "creek." I would rather give readers a poem that moves them the way the original moved its first readers than a precise list of what the poem contained.

Critics call this approach unfaithful. I think it is faithful to something more important than vocabulary. Consider a comic poem translated word for word: every word is correct, and the poem is no longer funny. Has the translator been faithful? The reader of that version will conclude that the poet had no sense of humor, which is the opposite of the truth.

Nor is literal accuracy as simple as it looks. Words in different languages rarely match one to one. A single word in the original may carry a color, a season, and a memory of childhood all at once, and its closest English partner may carry only the color. Every translator chooses which part of a word to keep; I simply admit that I am choosing.

I do not pretend that my versions are the originals. On the title page I write "versions by" rather than "translated by," and I encourage readers who want the literal sense to look for a word-for-word translation, of which there are usually several. Different translations can serve different needs. Mine is meant for the reader who wants, for a few minutes, to feel what it was like to read the poem for the first time.

1. The author of Passage A mentions reviewers who praised "a striking image" mainly to:
   • show that reviewers rarely read poems carefully.
   • argue that foreign poets deserve more attention.
   • suggest that translators should add images to ordinary poems.
   • illustrate how a loose translation can mislead readers about a poet.
2. As it is used in Passage A, the word "drifts" most nearly means:
   • floats on water.
   • moves away from the original.
   • piles up in heaps.
   • slowly becomes popular.
3. According to Passage A, how does its author deal with a poem whose sound cannot be preserved in English?
   • By keeping the images close to the original and adding a note about how the original sounds
   • By inventing new rhymes that imitate the original music
   • By refusing to translate poems that depend on sound
   • By publishing the original text beside a free version
4. In Passage B, the author describes a poem as "an event that happens to a reader" primarily to emphasize that:
   • poems should be read aloud in public.
   • readers often misunderstand difficult poems.
   • a poem's value lies largely in the experience it creates for a reader.
   • translators should explain every pun in a note.
5. The example of the comic poem in Passage B is used to support the claim that:
   • comic poems are easier to translate than serious ones.
   • critics are right to call free translation unfaithful.
   • readers prefer serious poems to funny ones.
   • a translation can be accurate word by word yet misrepresent the poet.
6. The author of Passage B writes "versions by" on the title page most likely in order to:
   • signal openly that the work is not a literal translation.
   • take credit for the original poems.
   • avoid paying the original poet.
   • show that the poems were written in English first.
7. Both authors would most likely agree that:
   • a translator should never change a poet's words.
   • word-for-word translation often fails to carry over a poem's sound or effect.
   • notes are the best way to explain a lost rhyme.
   • readers should learn the original language instead of reading translations.
8. The author of Passage A would most likely respond to Passage B's practice of replacing "river" with "stream" to keep a rhyme by saying that this practice:
   • is acceptable as long as the poem is comic.
   • is the only honest way to translate poetry.
   • risks giving readers a false picture of what the poet actually wrote.
   • will make the translation too long.
9. Which statement best describes a difference in how the two authors handle what their translations cannot preserve?
   • The author of Passage A ignores such losses, while the author of Passage B lists them on the title page.
   • Both authors add notes, but only the author of Passage B rhymes.
   • The author of Passage A invents puns, while the author of Passage B keeps the literal sense.
   • The author of Passage A explains losses in notes, while the author of Passage B points readers to other, literal translations.

Passage IV: Natural Science

Read the passage and choose the best answer to each question. Refer to the passage as often as necessary. This passage discusses sea otters, sea urchins, and kelp forests.

Along the rocky coasts of the North Pacific, forests grow under the sea. Giant kelp and other large brown algae anchor themselves to the seafloor with rootlike holdfasts and stretch toward the light, some growing tens of centimeters in a single day. The canopy they form near the surface shelters fish, crabs, snails, and seabirds. Yet these forests can vanish with surprising speed, and one of the clearest explanations for why involves an animal that rarely weighs more than forty-five kilograms: the sea otter.

Sea otters eat many kinds of shellfish, but sea urchins are among their favorite foods. Urchins, in turn, eat kelp. They are spiny, slow-moving grazers that usually feed on bits of drifting algae. When urchins are abundant and drifting food is scarce, however, they leave their crevices and move across the seafloor in large groups, chewing through the holdfasts that keep kelp attached to the rocks. A kelp plant with a severed holdfast floats away and dies. Where urchins graze unchecked, a dense forest can be reduced to what ecologists call an urchin barren: bare rock covered with urchins and little else.

The link among otters, urchins, and kelp became clear partly because of a historical accident. Hunters seeking the otters' thick fur killed so many during the eighteenth and nineteenth centuries that by the early twentieth century the species had disappeared from most of its range. A few small populations survived, including some in the Aleutian Islands of Alaska. When protection allowed those populations to grow, ecologists had a natural experiment: some islands had otters, and others nearby did not.

In the early 1970s, researchers compared such islands. Around islands with otters, urchins were small and scarce, and kelp forests were thick. Around islands without otters, urchins were large and plentiful, and the seafloor was largely bare. The difference was too striking to be explained by water temperature or rock type, which were similar from island to island. The researchers concluded that otters, by eating urchins, allowed kelp to flourish.

This pattern, in which a predator's effect passes down through the food chain to organisms it never eats, is known as a trophic cascade. Sea otters do not eat kelp, yet the presence or absence of otters can determine whether kelp forests exist. Ecologists call a species with such an outsized influence a keystone species, after the central stone that holds an arch together.

Kelp forests matter to people as well as to otters. They shelter young fish that later support commercial fisheries, soften the force of waves before they reach the shore, and draw carbon dioxide from the water as they grow. A shift from forest to barren therefore affects far more than a single food chain.

The story took an unexpected turn in the 1990s. Otter numbers in parts of the Aleutians, which had recovered for decades, began to fall sharply. Researchers eventually found evidence that killer whales, which had not been known to hunt otters often, had begun eating them. One hypothesis held that the whales had turned to otters after the seals and sea lions they usually ate became scarce. As the otters declined, urchin numbers rose, and kelp forests that had taken decades to return began to thin once more. The cascade had gained a new top level.

Other coasts have shown that otters are not the only check on urchins. Off southern California, where otters were absent for much of the twentieth century, kelp forests persisted in many places, apparently because lobsters and large fish preyed on urchins and because divers harvested urchins for food. When a disease outbreak killed large numbers of predatory sea stars along the Pacific coast of North America in the 2010s, urchin numbers exploded in some regions, and large areas of kelp were lost. Such cases suggest that a kelp forest is stable only when something, whether otter, lobster, sea star, or fisher, keeps urchins in check.

The lesson extends beyond the sea. Removing a single predator can change an entire landscape, often in ways that are hard to predict in advance. Restoring one, as the return of otters has shown, can sometimes bring a whole ecosystem back, though rarely in exactly its original form.

1. The main purpose of the passage is to:
   • describe the anatomy of giant kelp.
   • explain how predators of sea urchins, especially sea otters, can determine whether kelp forests survive.
   • argue that killer whales should be removed from the Aleutian Islands.
   • compare the fur trade in Alaska with that in California.
2. According to the passage, sea urchins destroy kelp forests by:
   • blocking sunlight from reaching the kelp.
   • eating the fish that fertilize the kelp.
   • spreading a disease among kelp plants.
   • chewing through the holdfasts that anchor kelp to the rocks.
3. According to the passage, urchins leave their crevices and graze in large groups when:
   • they are abundant and drifting food is scarce.
   • the water becomes too warm.
   • sea otters are nearby.
   • kelp forests are growing quickly.
4. The "historical accident" mentioned in paragraph 3 refers to:
   • a shipwreck that released urchins near the Aleutian Islands.
   • a mistake made by researchers in the 1970s.
   • the near elimination of sea otters by fur hunters, which left some islands with otters and others without.
   • the arrival of killer whales in Alaskan waters.
5. The researchers who compared islands in the 1970s ruled out water temperature and rock type as explanations because these conditions:
   • were similar from island to island.
   • had not been measured.
   • changed too quickly to study.
   • affected only the urchins.
6. Based on the passage, a keystone species is best described as a species that:
   • eats only one kind of food.
   • is the largest animal in its ecosystem.
   • lives at the center of a food web but has little influence.
   • has an unusually large effect on the structure of its ecosystem.
7. The statement "The cascade had gained a new top level" (paragraph 7) refers to the fact that:
   • kelp had begun to grow taller than before.
   • killer whales had begun preying on otters, adding a predator above them in the chain.
   • otters had begun to eat seals and sea lions.
   • researchers had discovered a new species of urchin.
8. The example of southern California in paragraph 8 mainly shows that:
   • sea otters have never lived off southern California.
   • kelp grows faster in warm water.
   • animals and people other than otters can keep urchin populations in check.
   • sea stars are the most important predators of kelp.
9. Suppose that in a southern California kelp forest with no otters and no urchin harvest, fishing removed most of the lobsters and large fish. Based on the passage, which outcome would be most likely?
   • Urchin numbers would rise, and the kelp forest would likely decline.
   • Urchin numbers would fall, and the kelp forest would grow thicker.
   • Sea stars would begin to eat kelp.
   • The kelp forest would be unaffected, since otters are absent.

Science (40 phút)

Passage I

Read the passage and study the figure, then choose the best answer to each question. You may NOT use a calculator on this section.

Students studied how soil temperature changes with depth during a single day. On a clear, calm summer day, they placed temperature probes at depths of 0 cm (the surface), 5 cm, 10 cm, 20 cm, and 40 cm in a bare, dry field. They recorded the soil temperature at each depth at 6 AM, 12 PM, and 6 PM. The results are shown in Table 1.

1. According to Table 1, at 12 PM, as depth increased from 0 cm to 40 cm, soil temperature:
   • increased only.
   • decreased only.
   • increased and then decreased.
   • decreased and then increased.
2. At which depth did the soil temperature change the least from 6 AM to 12 PM?
   • 0 cm
   • 5 cm
   • 10 cm
   • 40 cm
3. At 6 PM, the soil temperature at 10 cm was the same as the soil temperature at which other depth?
   • 0 cm
   • 5 cm
   • 20 cm
   • 40 cm
4. Based on Table 1, the soil temperature at 0 cm at 3 PM was most likely:
   • below 14 °C.
   • between 14 °C and 20 °C.
   • between 26 °C and 38 °C.
   • above 40 °C.
5. At 6 AM, soil temperature increased with depth. Which of the following statements is most consistent with this result?
   • Deeper soil received more sunlight during the night.
   • The soil surface lost heat during the night faster than the deeper soil did.
   • Soil temperature does not change with depth.
   • The soil at 40 cm was heated by the air above the field.
6. If the students had also measured soil temperature at a depth of 60 cm at 12 PM, the temperature would most likely have been closest to:
   • 14 °C.
   • 16 °C.
   • 18 °C.
   • 20 °C.
7. The difference between the soil temperature at 0 cm and the soil temperature at 20 cm was greatest at:
   • 12 PM.
   • 6 AM.
   • 6 PM.
   • all three times equally.

Passage II

Read the passage and study the figure, then choose the best answer to each question. You may NOT use a calculator on this section.

A student investigated how dissolving substances in water affects the temperature at which the water freezes.

Study 1: For each trial, the student dissolved a measured mass of a solute in 100 mL of distilled water at room temperature. The solutes were sodium chloride (NaCl, table salt), calcium chloride (CaCl₂, a salt used on icy roads), and sucrose (table sugar). Each solution was placed in a test tube, the tube was set in a bath of ice and rock salt, and a temperature probe recorded the temperature at which ice crystals first formed (the freezing point).

Study 2: The student prepared a second, identical set of solutions in identical plastic cups and placed all the cups at the same time in a freezer kept at -10 °C. The student recorded how long each solution took to freeze completely.

The results of both studies are shown in Table 1.

1. According to the results of Trials 1 through 5, as the mass of NaCl dissolved increased, the freezing point:
   • decreased only.
   • increased only.
   • increased and then decreased.
   • stayed the same.
2. Based on Trials 1 through 5, if 10 g of NaCl had been dissolved in 100 mL of water, the freezing point would most likely have been closest to:
   • -5.1 °C.
   • -5.8 °C.
   • -6.4 °C.
   • -8.0 °C.
3. When 4 g of solute was dissolved, which solute lowered the freezing point of water the LEAST?
   • NaCl
   • CaCl₂
   • All three lowered it by the same amount.
   • Sucrose
4. Which trials should be compared to determine how the identity of the solute affects the freezing point when the mass of solute is the same?
   • Trials 1, 2, and 3
   • Trials 3, 6, and 7
   • Trials 2, 4, and 6
   • Trials 5, 6, and 7
5. Based on Table 1, as the freezing point of a solution decreased, the time the solution took to freeze completely at -10 °C:
   • decreased only.
   • stayed about the same.
   • increased only.
   • increased and then decreased.
6. A classmate claims that equal masses of any solute lower the freezing point of water by the same amount. Do the results support this claim?
   • Yes, because all three solutes lowered the freezing point.
   • Yes, because NaCl and CaCl₂ produced the same freezing point.
   • No, because sucrose lowered the freezing point more than NaCl did.
   • No, because at 4 g, NaCl lowered the freezing point by 2.5 °C but sucrose lowered it by only 0.2 °C.
7. If a solution of 5 g of NaCl in 100 mL of water had been tested in Study 2, the time it took to freeze completely would most likely have been between:
   • 42 min and 48 min.
   • 48 min and 55 min.
   • 55 min and 63 min.
   • 63 min and 71 min.

Passage III

Read the passage and study the figure, then choose the best answer to each question. You may NOT use a calculator on this section.

Enzymes are proteins that speed up chemical reactions. Two enzymes that break down the same starch were compared: Enzyme X, taken from a mammal, and Enzyme Y, taken from a bacterium that lives in a hot spring. In each trial, equal amounts of enzyme and starch were mixed in a buffer at a set temperature, and the reaction rate (in micromoles of product formed per minute, µmol/min) was measured. Trials were run from 20 °C to 80 °C. The results are shown in Figure 1.

1. Of the temperatures tested, at which temperature did Enzyme X have its highest reaction rate?
   • 30 °C
   • 40 °C
   • 50 °C
   • 70 °C
2. Of the temperatures tested, what was the lowest temperature at which Enzyme Y had a higher reaction rate than Enzyme X?
   • 40 °C
   • 50 °C
   • 60 °C
   • 70 °C
3. As the temperature increased from 40 °C to 60 °C, the reaction rate of Enzyme X:
   • decreased only.
   • increased only.
   • increased and then decreased.
   • stayed the same.
4. The highest reaction rate measured for Enzyme Y was approximately how many times the highest reaction rate measured for Enzyme X?
   • About 0.5 times
   • About 1.2 times
   • About 2 times
   • About 5 times
5. Based on Figure 1, the reaction rate of Enzyme Y at 55 °C would most likely be:
   • below 22 µmol/min.
   • between 22 µmol/min and 45 µmol/min.
   • between 45 µmol/min and 78 µmol/min.
   • above 110 µmol/min.
6. Which of the following conclusions is best supported by Figure 1?
   • Enzyme X works best at higher temperatures than Enzyme Y does.
   • Both enzymes have the same optimal temperature.
   • Enzyme Y stops working at temperatures above 50 °C.
   • Enzyme Y is better suited to high temperatures, which is consistent with its source in a hot spring.
7. At 30 °C, the reaction rate of Enzyme X was approximately how many times the reaction rate of Enzyme Y?
   • About 2 times
   • About 3 times
   • About 5 times
   • About 10 times

Passage IV

Read the passage, which presents three viewpoints, then choose the best answer to each question. You may NOT use a calculator on this section.

A sealed bag of potato chips was filled and sealed at a factory near sea level, where the air pressure is about 101 kilopascals (kPa) and the air temperature was 20 °C. A hiker carried the unopened bag to a campsite at an elevation of 3,000 m, where the air pressure is about 70 kPa. At the campsite the bag sat in the sun, and its temperature was measured at 28 °C. The bag was noticeably puffier at the campsite than it had been at the factory. Three students offered explanations.

Student 1: The bag contains a fixed amount of gas. At the campsite, the outside air presses on the bag with much less pressure than at sea level. The gas inside expands until its pressure matches the lower pressure outside, so the bag puffs up. The temperature change had little effect. If the bag were carried back to sea level, it would return to its original size.

Student 2: The puffing was caused by the rise in temperature. The amount of gas in the bag did not change, but warm gas takes up more space than cool gas, so the gas expanded when the bag warmed in the sun. The change in air pressure had little effect. If the bag were cooled to 20 °C at the campsite, it would return to its original size.

Student 3: The chips themselves release gas over time, because oils in the chips slowly break down. During the days of the trip, the chips released enough gas to fill the bag further. Neither pressure nor temperature was important. The bag would stay puffy even if it were carried back to sea level, and an unopened bag left on a shelf at the factory for the same number of days would also become puffy.

1. Student 1's explanation depends mainly on a difference between the factory and the campsite in:
   • outside air pressure.
   • air temperature.
   • the amount of gas released by the chips.
   • the size of the bag.
2. Which student(s) would predict that an unopened bag left on a shelf at the factory for several days would become puffy?
   • Student 1 only
   • Student 2 only
   • Student 3 only
   • Students 1 and 3 only
3. Suppose the bag was placed in a cooler at the campsite until its temperature fell to 20 °C, and the bag remained just as puffy. This result would most directly weaken the explanation of:
   • Student 1 only.
   • Student 2 only.
   • Student 3 only.
   • Students 1 and 2.
4. Student 1 and Student 2 would most likely agree that:
   • the puffing was caused by the change in air pressure.
   • the puffing was caused by the change in temperature.
   • the chips released gas during the trip.
   • the amount of gas inside the bag did not change.
5. According to the passage, the air pressure at the campsite was approximately what percent of the air pressure at the factory?
   • About 30%
   • About 50%
   • About 70%
   • About 140%
6. Which of the following findings, if true, would most strongly support Student 3's explanation?
   • An empty bag sealed with only air also puffed up at 3,000 m.
   • A bag stored at sea level for a week became puffier, and its gas contained substances formed when oils break down.
   • A bag carried to 3,000 m and back returned to its original size.
   • A bag warmed to 28 °C at sea level became only slightly puffier.
7. Student 1 would most likely predict that if the same sealed bag were carried to a place where the air pressure is 55 kPa, the bag would be:
   • flatter than it was at the factory.
   • the same size as it was at the factory.
   • the same size as it was at the campsite.
   • puffier than it was at the campsite.

Passage V

Read the passage and study the figure, then choose the best answer to each question. You may NOT use a calculator on this section.

A biology class studied how light color and fertilizer affect the growth of bean seedlings. Eighty seedlings of the same variety, all 2 cm tall, were divided into 8 groups of 10. Each group was grown for 14 days under lamps of one color: red, blue, green, or white. All lamps produced the same light intensity, and all groups received the same amount of water at the same temperature. For each color, one group received no fertilizer, and the other group received the same dose of liquid fertilizer once a week. At the end of 14 days, the mean height of the seedlings in each group was measured. The results are shown in Figure 1.

1. Among the groups that received fertilizer, the seedlings grown under which light color had the lowest mean height?
   • Red
   • Blue
   • Green
   • White
2. For which light color did adding fertilizer increase the mean height by the greatest amount?
   • Red
   • Blue
   • Green
   • White
3. Which of the following was held constant for all 8 groups?
   • Light intensity
   • Light color
   • Use of fertilizer
   • Mean seedling height
4. Without fertilizer, the mean height of seedlings grown under red light was approximately how many times the mean height of seedlings grown under green light?
   • About 0.5 times
   • About 2 times
   • About 3 times
   • About 9 times
5. A student hypothesized that fertilizer increases the mean height of bean seedlings under every light color tested. Do the results support this hypothesis?
   • Yes, because for all four colors the group with fertilizer had a greater mean height than the group without it.
   • Yes, because the seedlings under red light grew the most.
   • No, because fertilizer had no effect under green light.
   • No, because the seedlings under blue light grew less with fertilizer.
6. The mean height of the seedlings grown with fertilizer under white light was how much greater than the mean height of the seedlings grown without fertilizer under red light?
   • 0.6 cm
   • 1.2 cm
   • 3.6 cm
   • 4.4 cm

Passage VI

Read the passage and study the figure, then choose the best answer to each question. You may NOT use a calculator on this section.

Scientists measured the dissolved oxygen (DO) concentration in a small, deep pond every other month for one year. Samples were taken just below the surface and just above the bottom of the pond. The results are shown in Figure 1. The surface water temperature on each sampling date was: January, 4 °C; March, 9 °C; May, 17 °C; July, 26 °C; September, 21 °C; November, 8 °C.

A species of fish that lives in the pond needs water with a DO concentration of at least 5.0 milligrams per liter (mg/L).

1. In which month was the DO concentration at the bottom of the pond highest?
   • January
   • March
   • May
   • November
2. According to Figure 1 and the passage, as the surface water temperature increased from January to July, the DO concentration at the surface:
   • increased only.
   • decreased only.
   • increased and then decreased.
   • stayed the same.
3. In which of the following months did the water at the bottom of the pond NOT meet the oxygen needs of the fish species described in the passage?
   • January
   • March
   • May
   • September
4. Based on the data, if the surface water temperature had been 13 °C, the DO concentration at the surface would most likely have been:
   • above 12.5 mg/L.
   • between 11.0 mg/L and 12.5 mg/L.
   • between 9.2 mg/L and 11.0 mg/L.
   • below 7.8 mg/L.
5. In which month was the difference between the surface DO and the bottom DO greatest?
   • July
   • May
   • March
   • January
6. The bottom DO concentration in November was approximately how much higher than the bottom DO concentration in September?
   • 3.5 mg/L
   • 6.9 mg/L
   • 10.4 mg/L
   • 13.9 mg/L