题目如下: 72. Biological functions of many plants and animals vary in cycles that are repeated every 24 hours. It is tempting to suppose that alteration in the intensity of incident light is the stimulus that controls these daily biological rhythms. But there is much evidence to contradict this hypothesis. Which of the following, if known, is evidence that contradicts the hypothesis stated in lines 2-5 above? (A) Human body temperature varies throughout the day, with the maximum occurring in the late afternoon and the minimum in the morning. (B) While some animals, such as the robin, are more active during the day, others, such as mice, show greater activity at night. (C) When people move from one time zone to another, their daily biological rhythms adjust in a matter of days to the periods of 。。。。。。 题目注释: A No reason is given to explain the variation of human body temperature throughout the day;this statement is irrelevant to the hypothesis. B No cause is given for the varied activity cycles of different animals;this statement is irrelevant to the hypothesis. 我的问题在上面说了,就是A和B的前半段解释没看懂。请高手指点,先谢了! |