2. 考研
  3. The Earth’ s daily clock, measured in a single revolution, is twenty-four hours. The human clock,【B1】______, is actually about t

The Earth’ s daily clock, measured in a single revolution, is twenty-four hours. The human clock,【B1】______, is actually about t

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问题     The Earth’ s daily clock, measured in a single revolution, is twenty-four hours. The human clock,【B1】______, is actually about twenty-five hours. That’ s 【B2】______ scientists who study sleep have determined from human subjects who live for several weeks in observation chambers with no【B3】______of day or night. Sleep researchers have 【B4】______ other surprising discoveries as well.
    We spend about one-third of our lives asleep, a fact that suggests sleeping, 【B5】______ eating and breathing, is a fundamental life process. Yet some people almost never sleep, getting by on as 【B6】______ as fifteen minutes a day. And more than seventy years of【B7】______into sleep deprivation, in which people have been kept【B8】______for three to ten days, has 【B9】______ only one certain finding: Sleep loss makes a person sleepy and that’ s about all; it causes no lasting ill【B10】______. Too much sleep, however, may be【B11】______for you.
    These findings【B12】______some long-held views of sleep, and they【B13】______questions about its fundamental purpose in our lives. In【B14】______, scientists don’t know just why sleep is necessary..
    Some scientists think sleep is more the result of evolutionary habit than【B15】______actual need, Animals sleep for some parts of the day perhaps because it is the 【B16】______ thing for them to do: it keeps them【B17】______and hidden from predators; it’s a survival tactic. Before the advent of electricity, humans had to spend at least some of each day in【B18】______and had little reason to question the reason or need for【B19】______. But the development of the electroencephalograph and the resulting discovery in 1937 of dramatic【B20】______in brain activity between sleep and wakefulness opened the way for scientific inquiry in the subject.
【B2】
选项 A、the
B、what
C、because
D、many
答案B
解析 考查语法知识。句子的谓语是is，空格处缺的必然是一个连词或关系词。B．what是关系代词，在从句中作表语，符合题意。what引导的这个表语从句比较复杂：who study sleep是定语从句，修饰scientists；定语从句who live for several weeks…day or night修饰先行词humansubjects。故B．what为正确答案。because是连词，表示原因。其他两项明显不符合题意，故排除。
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考研英语一

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