[单项选择]According to tile passage, scientists used isotopes from the water of the ice core to determine which of following
A. ( The amount of air that had bubbled to the surface since the ice had formed
B. ( The temperature of the atmosphere when the ice was formed
C. ( The date at which water had become locked in the glacier
D. ( The rate at which water had been frozen in the glacier

[单项选择]According to the passage, scientists used to think that the X-rays were produced by ______.
A. making sparks in laboratory
B. discharges of high-energy electron in the Sun, in exploding stars, and in lightning
C. electrons escaping their normal connections
D. radio waves

[单项选择]According to the passage, scientists are skeptical toward their equations because scientists ______.


A. work to explain real, rather than theoretical or simplified situations
B. know that well-defined problems are often the most difficult to solve
C. are unable to express their data in terms of multiple variables
D. are unwilling to relax the axioms they have developed

[单项选择]According to the passage, scientists have decided that sulfur aerosols from volcanic eruptions affect global temperatures to a greater extent than ash clouds because
A. (A) the greenhouse gas effect produced by human activities tends to have a much greater environmental effect than that of volcanic explosions
B. (B) clouds of sulfur-rich gases tend to achieve greater heights in the stratosphere than do ash clouds
C. (C) a particular explosion producing high sulfur and little ash had a greater environmental effect than the converse
D. (D) the burning of fossil fuels tends to exacerbate the effects of sulfurous aerosols, but not those of ash clouds
E. (E) global warming effects tend to minimize the impact of ash clouds, but not those of sulfurous aerosols

[单项选择]According to the passage, scientists have positively confirmed that the brains of narcoleptics differ from those of normal brains in which of the following ways
A. (A) Narcoleptic brains tend to remove degenerative tissue at a more prolific rate than that of nonnarcoleptics.
B. (B) Narcoleptics are less responsive to drugs which treat neural autoimmune dysfunction than are nonnarcoleptics.
C. (C) Nonnarcoleptics do not possess the same neurological immune antigens as narcoleptics.
D. (D) Neurons that control muscle tone are damaged in the brains of narcoleptics, but not in those of non-narcoleptics.
E. (E) Narcoleptics experience greater neural degeneration as a result of aging than do nonnarcoleptics.

[单项选择]According to the passage, why some scientists are thinking twice about doing or reporting their research
A. Because they are lack of fund.
B. Because they have to share the honor with others.
C. Because their research may arouse Controversy.
D. Because the government bans them from publishing the results of their research.

[单项选择]According to the passage, what will scientists most probably do in the future
A. They will work hard to reduce ocean noise pollution.
B. They will protect animals from harmful noises.
C. They will try to set a limit of 120 decibels.
D. They will study the effect of ocean noise pollution.

[单项选择]According to passage, scientists failed to______.


A. discover the characteristic of nuclear process
B. discover the nature of uranium ore
C. save the life of uranium miners
D. store nuclear wastes in underwater tanks

[单项选择]We can learn from the passage that Blackpool used to
A. have as many beaches as Luxemburg.
B. have seriously polluted drinking water.
C. boast some imposing seafront sights.
D. attract few domestic holiday makers.

[单项选择]According to the passage, scientists cannot explain which of the following aspects of squirrel behavior
A. Where squirrels store their acorn caches
B. Why squirrels prefer acorns over other seeds
C. Why squirrels eat only a portion of each acorn they retrieve
D. Why squirrels prefer acorns from a particular species of oak trees

[单项选择]According to the passage, what can scientists do now with the genetic testing technology