The term biological clock is applied to the means by which living things adjust their activity patterns, without any【B1】______ c

admin2016-03-29  16

问题     The term biological clock is applied to the means by which living things adjust their activity patterns, without any【B1】______ cue, to the time of day, or the month, or the year. The biological clocks seem to be beautifully【B2】______ the needs of living things. They are affected but little, if at all, by drugs, chemicals, or wide temperature difference—【B3】______ which may alter substantially the rates of all ordinary processes of the body.
    The nature of the biological clocks’【B4】______ is still a mystery. Two quite different theories can【B5】______ them. According to the first of these theories, each individual contains its own independent timing system. This is believed to have【B6】______, aided by natural selection, as an adaptation to the rhythmic environment. It has now become independent of the environment. The other theory holds that living things react【B7】______ to their rhythmic physical environment. The setting of their biological clocks, therefore, 【B8】______ a constant adjustment to subtle environment forces. But the search for the【B9】______ timing system has been futile thus far. Not only has no independent timing system ever been discovered, but there has not yet been even a guess【B10】______ its nature.
【B5】

选项

答案account for

解析 根据空格前的can可知,此空需要原形动词(词组)。account for“解释,说明”。
转载请注明原文地址:https://kaotiyun.com/show/kPe7777K
0

最新回复(0)