单选题 . ①Prominent among theories of the function of sleep is Meddis' immobilization hypothesis, which holds that sleep, rather than serving a restorative function, plays a protective role during times that animals cannot be usefully engaged in other activities. ②Meddis reasoned that animals not immediately threatened by predators would be safer if they passed the time sleeping. ③Sleep would prevent an animal from moving or responding to nonthreatening stimuli in ways that might attract the attention of predators.
①However, that hypothesis cannot easily explain why one often observes a rebound in sleep time or intensity following a period of sleep deprivation. ②Neither does the hypothesis explain the existence of various states of sleep, which themselves may be associated with different functions.31. According to the passage, the immobilization hypothesis fails to account for which of the following facts? ______

A、 That sleep does not appear to be a uniform and unchanging state
B、 That under certain conditions animals appear to need more sleep than usual
C、 That animals rarely sleep when a predator has been detected nearby

【正确答案】 A、B

【答案解析】 A：本题问的是“不移动假说没能解释什么”，因此定位到第二段。本题属于细节题，因此正确答案应该是定位部分的同义改写。not...uniform and unchanging state改写第二段第②句中的various states of sleep。
B：certain conditions、more sleep than usual分别改写第①句中的following a period of sleep deprivation、rebound in sleep time or intensity。
C：第二段中未提及。