Questions 51-56 are based on the following passage.
As viewed from space, the Earth's distinguishing characteristics are its blue waters and white clouds. Enveloped by an ocean of air consisting of 78% nitrogen and 21% oxygen, the planet is the only one in our solar system known to harbor life. Circling the Sun at an average distance of 149 million km (93 million miles), the Earth is the third planet from the Sun and the fifth largest planet in the solar system. Its rapid spin and molten nickel-iron core give rise to an extensive magnetic field which, coupled with the atmosphere, shields us from nearly all of the harmful radiation coming from the Sun and other stars. Most meteors burn up in the Earth's atmosphere before they can strike the surface. The planet's active geological processes have left no evidence of the ancient pelting it almost certainly received soon after it was formed. The Earth has a single natural satellite —— the Moon.
51. Approximately how much of the Earth's atmosphere is nitrogen?
A. One-fourth
B. One-half
C. Three-fourths
D. All of it
52. Which of the following helps to create the Earth's magnetic fields?
A. Its blue waters
B. Its nitrogen atmosphere
C. Its molten metal core
D. The Moon
53. What two factors help protect the Earth from radiation?
A. Magnetic field and atmosphere
B. Rapid spin and molten iron-nickel core
C. The Sun and the Moon
D. Blue waters and white clouds
54. Why does the Earth show almost no signs of having been hit by numerous meteors in the past?
A. Humans have built over most of the craters.
B. Most meteors fell into the ocean and not on land.
C. The Earth's magnetic field repelled most meteors.
D. The Earth's natural geologic activity has eliminated most traces.
55. The main idea of this passage is that
A. there are life-supporting characteristics on the Earth.
B. The Earth is predominantly water.
C. The Earth has no common characteristics with other planets.
D. The Earth is the only planet with a moon.
56. This selection leads one to believe that
A. The Earth never gets hit by meteors.
B. The Earth always gets hit by meteors.
C. The Earth was hit by meteors some time in the past.
D. The Earth may be bombarded by meteors in the near future.
Questions 57-62 are based on the following passage.
Since life began eons ago, thousands of creatures have come and gone. Some, such as the dinosaurs, became extinct due to naturally changing ecologic conditions. More recent threats to life forms are humans and their activities. Man has drained marshes, burned prairies, dammed and diverted rivers. Some of the more recent casualties of man's expansion have been the dodo, great auk, passenger pigeon, Irish elk, and Steller's sea cow. Sadly, we can no longer attribute the increasing decline in our wild animals and plant species to "natural" processes. Many species are dying out because of exploitation, habitat alteration or destruction, pollution, or the introduction of new species of plants and animals to an area. As mandated by Congress, protecting endangered species, and restoring them to the point where their existence is no longer jeopardized, is the primary objective of the U.S. Fish and Wildlife Service's Endangered Species Program.
57. Which of the following is a form of man's habitat alteration?
A. Glacial encroachment
B. Hurricanes
C. Dammed rivers
D. Snowstorms
58. Which of the following has become extinct due to man's destruction?
A. African elephant
B. Irish elk
C. Giant panda
D. White Bengal
59. Which of the following would be a likely theme for the next paragraph?
A. Naturally changing ecological conditions
B. Animals that have become extinct
C. Achievements of the government Endangered Species Program
D. Programs that have destroyed natural habitats
60. The tone of this passage is
A. nationalistic.
B. pro-wildlife.
C. anti-wildlife.
D. feminist.
61. According to this passage,
A. man is the cause of some animal extinction.
B. animals often bring about their own extinction.
C. Congress can absolutely end extinction of animals.
D. a law is more important than human responsibility.
62. Which of the following is NOT a cause of increasing decline of wild animal population?
A. Exploitation
B. Pollution
C. Habitat alteration
D. Congressional law
Questions 63-68 are based on the following passage.
The "Karat" marking on jewelry tells you what proportion of gold is mixed with other metals. If 14 parts of gold are mixed with 10 parts of base metal, the combination is called 14-Karat (14K) gold. The higher the Karat rating, the higher the proportion of gold in the object. The lowest Karat gold that can be marketed in the United States is 10-Karat gold. Jewelry does not have to be marked with its Karat quality, but most of it is. If there is a Karat quality mark, next to it must be the U.S. registered trademark of the person or company that will stand behind the mark, as required by the National Gold and Silver Stamping Act.
63. If a ring is stamped 24K, it has
A. 204 parts of gold.
B. 24 parts of gold.
C. two and four-tenths parts of gold.
D. 10 parts of gold.
64. Gold which is 10 Karats in proportion
A. represents the highest grade of gold in the U.S.
B. cannot be sold in the U.S.
C. never carries a Karat quality mark.
D. represents the lowest-grade gold marketable in the U.S.
65. If gold is marked with a Karat quality mark, it must also
A. bear a national gold and silver stamp.
B. bear the registered trademark of the entity standing behind the mark.
C. bear a "made in the USA" mark.
D. bear a percentage mark.
66. If the jewelry is marked 14 parts of gold mixed with 10 parts of base metal it will always bear
A. a 14K mark.
B. a 10K mark.
C. an 18K mark.
D. a platinum mark.
67. This paragraph serves the consumer as
A. important buying information.
B. a challenge to buy more gold.
C. a debate over gold prices.
D. advice about buying silver.
68. The Stamping Act is
A. a regulation for tax.
B. rule of law.
C. a law that makes such stamping mandate.
D. an implement.
Questions 69-75 are based on the following passage.
Mr. Faugel was convinced that student nervousness had affected their scores; to reduce the anxiety of these students who had already been tested, he gave 22 of them a beta blocker before readministration of the test. Their scores improved significantly. The other 8 students (who did not receive the beta blockers) improved only slightly. Second-time test-takers nationwide had average improvement
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