单选题There is no creature that does not need sleep or complete rest every day. If you want to know why, just try going without sleep for a long period of time. You will discover that your mind and body would become too tired to work properly. You would become irritable and find it hard to think clearly or concentrate on your work. So sleep is quite simply the time when the cells of your body recover from the work of the day and build up supplies of energy for the next period of activity. One of the things we all know about sleep is that we are unconscious in sleep. We do not know what is going on around us. But that doesn' t mean the body stops all activity. The important organs continue to work during sleep, but most of the body functions are slowed down. For example, our breathing becomes slower and deeper. The heart beats more slowly, and the blood pressure is lower. Our arms and legs become limp(柔软的) and muscles are at rest. It would be impossible for our body to relax to such an extent if we were awake. So sleep does for us what the most quiet rest can not do. Your body temperature becomes lower when you are asleep, which is the reason people go to sleep under some kind of covers. And even though you are unconscious, many of your reflexes(反射 动作) still work. For instance, if someone tickles(使觉得痒) your foot, you will put it away in your sleep, or even brush a fly from your forehead. You do these things without knowing it.

单选题Woman: I’ve just been reading through your last project report.Man: I hope you didn’t find much wrong in it.A. On the contrary B. On the other handC. Don't forget D. Don't be silly

单选题—He hasn't gone to the office up to now. —Well, he ______.A. shouldB. ought toC. ought to goD. ought to have

单选题A: Good morning, madam. I wonder if you could spare me a few minutes of your time? B: ______ A: Well, actually I represent the New British Encyclopedi

单选题The United States court system is characterized by ______ hierarchies: there are both state and federal courts.(2004年武汉大学考博试题)

单选题She had a strong ______ to give a talk about her experiences, because she didn't like the limelight.

单选题She missed the train because she had been______ the traffic jam.

单选题Thank you for applying for a position with our firm. We do not have any openings at this time, but we shall keep your application on ______ for months.

单选题His plane is due at 10 in Pads. Look, ______ plane is now at ______ airport. A．a/the B．the/the C．the/an D．a/an

单选题Schliemann knew, ______ he saw it, that he had found the actual place where the ruins of Troy were buried.

单选题According to Geoff Stewart, the high court's decision will ______.

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单选题The original canal was twice broadened for the larger modern boats.

单选题The auctioneer may decide to sell the "Lots" out of order because ______. ( )

单选题The objective mentioned by the author to be achieved is to ______. A．raise peoples consciousness about software security B．provide practical information C．understand the importance of electronic component reliability D．both A and B