题目内容
（请给出正确答案）
关于直埋电缆光缆敷设的表述中，正确的是 ()
A.一般情况下，直埋电缆、光缆的埋深应为0．5～0．7m
B.直埋电缆、光缆应有覆盖物保护，无须设标志
C.直埋电缆、光缆穿过电车轨道或铁路轨道时，应设于水泥管或钢管等保护管内
D.其埋深可以低于管道埋深的要求
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更多“关于直埋电缆光缆敷设的表述中，正确的是 （)”相关的问题
第1题
It is natural for a laborer to imagine that the______(few)hours he has to spend laboring, and the more hours he is free to play, the better.
第2题
A surgeon who has worked 40 hours in a row without sleep ______.
A．may ignore the potential risk of insufficient sleep
B．will remain alert because he is used to it
C．can still provide quality medical care
D．should be fired if he continues the medical operation
第3题
Are You Getting Enough Sleep？
What happens if you don't get enough sleep？ Randy Gardner,a high school student in the UnitedStates,wanted to find out. He designed an experiment on the effects of sleeplessness for a school science project. With doctors watching him carefully,Gardner stayed awake for 264 hours and 12 mi-nutes. That's eleven days and nights without sleep !
What effect did sleeplessness have on Gardner？ After 24 hours without sleep, Gardner started havingtrouble reading and watching television The words and pictures were too blurry(模糊). By the third day,hewas having trouble doing things with his hands. By the fourth day, Gardner was hallucinating(产生幻觉). Forexample,when he saw a street sign, he thought it was a person. He also imagined he was a famous footballplayer Over the next few days,Gardner's speech became so slurred(楚)that people couldn't understandhim He also had trouble remembering things. By the eleventh day,Gardner couldn't pass a counting test. Inthe middle of the test he simply stopped counting. He couldn't remember what he was doing.
When Gardner finally went to bed, he slept for 14 hours and 45 minutes. The second night he sleptfor twelve hours, the third night he slept for ten and one-half hours,and by the fourth night, he had re-turned to his normal sleep schedule.
Even though Gardner recovered quickly, scientists believe that going without sleep can be danger-ous. They say that people should not repeat Randy's experiment. Tests on white rats have shown howserious sleeplessness can be. After a few weeks without sleep,the rats started losing their fur(皮毛).And even though the rats ate more food than usual, they lost weight. Eventually the rats died.
During your lifetime,you will probably spend 25 years or more sleeping. But why？ What is thepurpose of sleep？ Surprisingly,scientists don't know for sure. Some scientists think we sleep in orderto replenish(补充)brain cells. Other scientists think that sleep helps the body to grow and to relievestress. Whatever the reason,we know that it is important to get enough sleep.
Randy Gardner studied the effects of over-sleeping.
A.Right
B.Wrong
C.Not mentioned
第4题
Why did Gregory Belenky restrict his subjects to odd numbers of sleep hours？
A．Because he could acquire more precise information.
B．Because he could provide different tests.
C．Because he could find out the utmost effects of sleep.
D．Because he could observe the relationship between sleep and cognition.
第5题
A surgeon who has worked 40 hours in a row without sleep ______.
A．can still provide quality medical care
B．will remain alert because he is used to it
C．may ignore the potential risk of insufficient sleep
D．should be fired if he continues the medical operation
第6题
A surgeon who has worked 40 hours in a row without sleep ______.
A．can still provide quality medical care
B．will remain alert because he is used to it
C．may ignore the potential risk of insufficient sleep
D．should be fired if he continues the medical operation
第7题
听力原文： Judging from recent surveys, most experts in sleep behavior. agree that there is virtually an epidemic of sleepiness in the United States. The beginning of this sleep-deficit crisis can be traced to the invention of light bulb a century ago. In the 18th or 19th century, the average person used to sleep about 9. 5 hours a night. The best sleep habits were forced on people of that time, because it was dark and people had nothing to do in the evening on the farm.
By the 1950s and 1960s, the sleep schedule had been reduced dramatically to between 7.5 and 8 hours on average. Most people had to wake to an alarm clock. People cheat on their sleep, but they don't realize they are doing it. They think they are OK because they can get by on 6.5 hours, when they really need 8 hours or even more to feel ideally vigorous.
Perhaps the most merciless robber of sleep, researchers say, is the complexity of the day. Whenever pressure from work, study and family, etc. mounts, many people consider sleep the least expensive item on his program. In the United States, one is considered dynamic if he says he only needs 5 hours' sleep, whereas if he has to get 8.5 hours, people think he lacks drive and ambition.
The consequences of sleep deficit are obvious. When researchers put subjects through a set of psychological and performance tests, they found that people in sleep deficit showed weakened short-term memory as well as poor abilities to make decisions and to concentrate.
(22)
A．Because they had no ambition.
B．Because they had a good sleep habit.
C．Because they had nothing to do.
D．Because there was no electric lighting.
第8题
A．Y
B．N
C．NG
第9题
Two groups of people are compared in the third study. They are people______.
A．with less than5 hours of sleep a night and with 7 to 9 hours of sleep
B．who slept 4 hours a night and who slept 4 hours for 2 nights
C．with less than 4 hours of sleep a night and with 7 to 9 hours of sleep
D．with less than 5 hours of sleep a night and with 8 hours of sleep
第10题
To determine the 【40】______ of the lack of sleep, scientists have put 【41】______ through a set of psychological and performance tests 【42】______ them, for instance, to add columns of numbers or recite a passage read to them only minutes earlier, "We've found that if you're in sleep 【43】______ , performance suffers," says Dr. David. "Short-term memory is 【44】______ , 【45】______ are abilities to make decisions and to concentrate."
【26】
A．for
B．at
C．in
D．since
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