At the beginning of last century, medical scientists made an interesting discovery: we are built not just of flesh and blood but also of time. They were【C1】______to show that we all have "a body clock" inside us, which controls the【C2】______and fall of our body energies, making us different from one day to the next. The【C3】______of "a body clock" should not be too surprising since the lives of most living things are controlled【C4】______the 24 hour night-and-day cycle. We feel tired and fall asleep at night and become【C5】______and energetic during the day. If the 24 hour-cycle is disturbed, most people experience unpleasant【C6】______For example, people who are not used to working at night can find that【C7】______of sleep cause them to perform badly at work. 【C8】______the daily cycle of sleeping and waking, we also have other cycles which【C9】______longer than one day. Most of us would agree that we feel good on some days and not so good on【C10】______: sometimes our ideas seem to flow and at other times, they just do not exist.
单选题
【C1】
【正确答案】
B
【答案解析】解析：本题考查词义辨析。上文提到上世纪初，科学家就已经发现人体不仅由血肉组成，还有时间。因此，根据这个发现，他们能够证明在人体内存在生物钟，故选B。beanxious to do，“渴望做某事”，此处并没有强调科学家的心理活动，故排除A。