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 concen-
tration 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.
为什么是B不是D??
can the fact that inactive areas of brain release some adenosine supports that the hypothesise that it is the cumulative binding of adenosine to a large number of sites that causes the onset of sleep?
而B从反面证明了结论。
我对题目的翻译理解有很大的问题
这边说chemical被释放when cells active
然后A chemical受限于cells的sites,当A chemical↑→wakefulness
sites↓→sleep
所以學者結論是：sites↑→oneset of sleep
不是很矛盾馬
為什麼學者的結論跟前面講的是相反的？
是我理解有問題馬
求助~~~~~
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