The brain waves are the slowest during ____
A) stage 1
B) stage 2 and stage 3
C) stage 4
D) REM sleep
本题为单选题,请给出正确答案及解析,谢谢!
A) stage 1
B) stage 2 and stage 3
C) stage 4
D) REM sleep
本题为单选题,请给出正确答案及解析,谢谢!
第1题
One of the features of REM sleep is that______.
A.there are large slow waves, though rapid for the first few minutes
B.you have the deepest sleep
C.there are no brain waves
D.the brain waves are a little last and the brain becomes a little active
第2题
After you have reached the deepest sleep,______.
A.you will stay at the fourih stage the rest of the night
B.you will lose your consciousness for 40-60 minutes
C.your brain waves will show the delta rhythm
D.your brain waves will show the alpha rhythm
第3题
The brain controls the other body activities through______.
A.medical devices
B.small electrodes
C.he brain waves
D.the nerve cells
第4题
The brain waves are the slowest during______.
A.stage 1
B.stage 2 and stage 3
C.stage 4
D.REM sleep
第5题
A) there are large slow waves, though rapid for the first few minutes
B) you have the deepest sleep
C) there are no brain waves
D) the brain waves are a little fast and the brain becomes a little active
本题为单选题,请给出正确答案及解析,谢谢!
第6题
After you have reached the deepest sleep, ______.
A.you will stay at the fourth stage the rest of the night
B.you will lose your consciousness for 40-60 minutes
C.your brain waves will show the delta rhythm
D.your brain waves will show the alpha rhythm
第7题
Questions 26 to 30 are based on the following passage:
Sleep is part of a person's daily activity cycle. There are several different stages of sleep, and they too occur in cycles. If you are an average sleeper, your sleep cycle is as follows. When you first drift off into slumber (安睡), your eyes will roll about a bit, your temperature will drop slightly, your muscles will relax, and your breathing were slow and become quite regular. Your brain waves slow down a bit too, with the alpha rhythm of rather fast waves predominating for the first few minutes. This is called stage 1 sleep. For the next half hour or so, as you relax more and more, you will drift down through stage 2 and stage 3 sleep. The lower your stage of sleep, the slower your brain waves will be. Then about 40 to 60 minutes after you lose consciousness you will have reached the deepest sleep of all. Your brain waves will show the large slow waves that are known as the delta rhythm. This is stage 4 sleep.
You do not remain at this deep fourth stage all night long, but instead about 80 minutes after you fall into slumber, your brain activity level will increase again slightly. The delta rhythm will disappear, to be replaced by the activity pattern of brain waves. Your eyes will begin to dart around under your closed eyelids (眼皮) as if you were looking at something occurring in front of you. This period of rapid eye movement lasts for some 8 to 15 minutes and is called REM sleep. It is during REM sleep period, your body will soon relax again, your breathing will grow slow and regular once more, and you will slip gently back from stage 1 to stage 4 sleep — only to rise once again to the surface of near consciousness some 80 minutes later.
26.The stages of sleep take on ____.
A) an irregular aspect. B) a regular aspect C) a punctual aspect D) a similar aspect
27.Stage 4 sleep lasts ____.
A) about 80 minutes
B) about 40 60 minutes
C) about 30 munutes
D) about 20 40 minutes
28.The brain waves are the slowest during ____.
A) stage 1 C) stage 4 B) stage 2 and stage 3 D) REM sleep
29.In the second paragraph the word “dart” means ____.
A) glare B) move rapidly or suddenly C) stop moving D) gaze
30.One of the features of REM sleep is that ____.
A) there are large slow waves, though rapid for the first few minutes
B) you have the deepest sleep
C) there are no brain waves
D) the brain waves are a little fast and the brain becomes a little active
第8题
The first paragraph of this passage tells us about ______.
A.the rhythms of brain waves
B.the daily activities of sleep
C.the stages of sleep in cycles
D.the daily activities in cycles
第9题
What Is Death?
People in the past did not question the difference between life and death. They could see that a person died when his heart stopped beating. People have learned, however, that the body does not die immediately when the heart stops beating. They discovered that we remain alive as long as our brain remains active. Today the difference between life and death is not as easy to see as in the past. Modern medical devices can keep the heart beating and the lungs breathing long after the brain stops. But is this life?
This question has caused much debate among citizens in the United States. Many of them want a law that says a person is dead when the brain dies. A person should be considered dead when brain waves stop even if machines can keep the body alive. Such a law would permit doctors to speed removal (切除) of undiseased (没病的) organs for transplant (移植) operations.
The brain is made of thousands of millions of nerve cells. These cells send and receive millions of chemical and electrical messages every day. In this way the brain controls the other body activities. Nerve-cell experts say it is usually easy to tell when the brain has died. They put small electrodes (电极) on a person's skull (头骨) to measure the electrical signals that pass in and out of the brain. These brain waves are recorded on a television screen or on paper. The waves move up and down every time the brain receives messages from the nerve cells. The brain is dead when the waves stop moving.
Although there are people who oppose the idea of a law on brain block for various reasons, the idea of brain wave activity as a test of death is slowly being accepted.
第 31 题 People in the past held that the difference between life and death
A.did not exist.
B.was easy to tell.
C.lay in the brain.
D.was open to debate.