不懂啊，求答案，求解释

CrapSociety

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.

victoria_cc

感觉B不对，B范围貌似不太好，作者假设的是影响睡觉，而B选项说的是影响清醒..

CrapSociety

答案就是B

wintertrain

这题的确很怪，我猜测是不是adenosine to a large number of sites按照短文讲的应该是wakefulness，但结论却说是causes the onset of sleep，所以就要有东西阻止 the binding of adenosine to sites on brain cells，也就是答案B。不知道我的理解对不对，仅供参考！

wintertrain

按照大牛的解题方法就是Support题型里的假设类支持：将原文的推理中的GAP填补。消除原文的推理缺陷。不知道我对大牛逻辑方法的解读是否正确？供楼主参考吧！

CloverJackier

B是正確的，認真看題目，說人從清醒（也就是原文說的brain cell active）開始就不斷釋放A，然後A就開始和brain cell 結合，隨著人清醒時間越長，A和brain cell 結合得就越多；但是又發現當人睡著以後呢，結合的就變少了，所以就懷疑：是A和brain cell 結合太多了把人搞困了。

B選項，我們估且不觀他是不是咖啡因還是大便，總之，說的核心是能阻止A和brain cell 結合就能讓人不困，完美反證結合了就困

注意題目關心的是從不睡到睡的轉換，所以，A選項說睡著以後的事情於本題無關，C的body 沒提過，DE也無關

wintertrain

楼上大牛说得有道理，顶！
谢谢大牛指导