题目内容
When we listen to a person talking, the most important thing for us to do is to ________ .
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The author most probably is a ________ .
Passage 2There is no creature that does not need sleep or complete rest every day.If you want to knowwhy, just try going without sleepfor a long period of time. You will discover thatyour mind and body would become loo tired to work properly. You would become imitable and find it hardto think clearly or concentrate on your work. So sleep is quite simply the time when the cells of your bodyrecover 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 unconsciousin sleep. We do not know whatis going on around us. But that doesn't mean the body stops all activity. The important organs continue towork 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 bloodpressure is lower. Our arms and legs become limp and muscles are at rest. It would be impossible for ourbody 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 sleepunder some kind of covers. And even though you are unconscious, many of your reflexes still work. Forinstance, if someone tickles your foot, you will put it away in your sleep, or even brush a fly from yourforehead. You do these things without knowing it.66. If you don't have as much sleep as your body needs, you will ________ .
In the clause".. that we are unconscious in sleep"(Paragraph 3), the word "unconscious" means _______ .
Passage 3Space is a dangerous place , not only because of meteors but also because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on earth. Light gets through, and this is essential for plants to make the food which we eat. Heat , too , makes our environment endurable. Various kinds of rays come through the air from outer space，but enormous quantities of radiation from the sun are screened off. As soon as men leave the atmosphere they are exposed to this radiation. But their spacesuits or the walls of their spacecraft, if they are inside, do prevent a lot of radiation damage.Radiation is the greatest known danger to explorers in space. The unit of radiation is called”rem”. Scientists have reason to think that a man can put up with far more radiation than 0.1 rem without being damaged; the figure of 60 rems has been agreed on. The trouble is that it is extremely difficult to be sure about radiation damage- a person may feel perfectly well, but the cells of his or her sex organs may be damaged, and this will not be discovered until the birth of deformed children or even grandchildren. Missions of the Apollo flights have had to cross belts of high radiation and ，during the outward and return journeys, the Apollo crew accumulated a large amount of rems. So far , no dangerous amounts of radiation have been reported, but the Apollo missions have been quite short. We simply do not know yet how men are going to get on when they spend weeks and months outside the protection of the atmosphere, working in a space laboratory. Drugs might help to decrease the damage done by radiation, but no really effective ones have been found so far.71. According to the first paragraph, the atmosphere is essential to man in that ______ .
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