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36. GWD25-Q36
The chemical adenosine is released by brain cells when those cells are active. Adenosine then binds to more and more sites on cells in certain areas of the brain, as the total amount released gradually increases during wakefulness. During sleep, the number of sites to which adenosine is bound decreases. Some researchers have hypothesized that it is the cumulative binding of adenosine to a large number of sites that causes the onset of sleep.
Which of the following, if true, provides the most support for the researchers’ hypothesis?
A. Even after long periods of sleep when adenosine is at its lowest concentration in the brain, the number of brain cells bound with adenosine remains very large.
B. Caffeine, which has the effect of making people remain wakeful, is known to interfere with the binding of adenosine to sites on brain cells.
C. Besides binding to sites in the brain, adenosine is known to be involved in biochemical reactions throughout the body.
D. Some areas of the brain that are relatively inactive nonetheless release some adenosine.
E. Stress resulting from a dangerous situation can preserve wakefulness even when brain levels of bound adenosine are high.
答案选b，我怎么觉得是weaken而不是support呢？
40. GWD-23-Q14
Plantings of cotton bioengineered to produce its own insecticide against bollworms, a major cause of crop failure, sustained little bollworm damage until this year. This year the plantings are being seriously damaged by bollworms. Bollworms, however, are not necessarily developing resistance to the cotton’s insecticide. Bollworms breed on corn, and last year more corn than usual was planted throughout cotton-growing regions. So it is likely that the cotton is simply being overwhelmed by corn-bred bollworms.
In evaluating the argument, which of the following would be most useful to establish?
A. Whether corn could be bioengineered to produce the insecticide
B. Whether plantings of cotton that does not produce the insecticide are suffering unusually extensive damage from bollworms this year
C. Whether other crops that have been bioengineered to produce their own insecticide successfully resist the pests against which the insecticide was to protect them
D. Whether plantings of bioengineered cotton are frequently damaged by insect pests other than bollworms
E. Whether there are insecticides that can be used against bollworms that have developed resistance to the insecticide produced by the bioengineered cotton
答案选b,能讲解下吗？
40. GWD-23-Q14
Plantings of cotton bioengineered to produce its own insecticide against bollworms, a major cause of crop failure, sustained little bollworm damage until this year. This year the plantings are being seriously damaged by bollworms. Bollworms, however, are not necessarily developing resistance to the cotton’s insecticide. Bollworms breed on corn, and last year more corn than usual was planted throughout cotton-growing regions. So it is likely that the cotton is simply being overwhelmed by corn-bred bollworms.
In evaluating the argument, which of the following would be most useful to establish?
A. Whether corn could be bioengineered to produce the insecticide
B. Whether plantings of cotton that does not produce the insecticide are suffering unusually extensive damage from bollworms this year
C. Whether other crops that have been bioengineered to produce their own insecticide successfully resist the pests against which the insecticide was to protect them
D. Whether plantings of bioengineered cotton are frequently damaged by insect pests other than bollworms
E. Whether there are insecticides that can be used against bollworms that have developed resistance to the insecticide produced by the bioengineered cotton
答案选c， |
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发表于 2010-10-10 20:25:49
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