英语四级阅读练习题答案讲解

英语四级阅读练习题答案讲解
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
26.答案B。

文章的第二句告诉我们睡眠的不同阶段是周期性发生的，故睡眠的各阶段呈现规则的一面。

27.答案D。

根据文章可知一个睡眠周期大约是 80分钟，而stage 4 sleep是睡眠的
最后阶段，它发生在入睡后大约40至60分钟时，据此可推出stage 4 sleep持续20至
40分钟。

28.答案C。

文章第一段倒数第四句说“睡得越深，脑电波就越慢”，而 stage 4 sleep 是睡得最深的，故脑电波也是最慢的。

29.答案B。

dart的后文说“眼睛好像看着发生在眼前的事”，又说“这种快速移动
眼睛的阶段叫 REM sleep”，据此可知dart意为move quickly or suddenly飞快地移动。

glare怒目而视;gaze凝视。

30.答案D。

从第二段第一、二句可知大脑运动水平会再度略有提高，而 delta波消失，取代的是脑电波运动图形。

据此可知脑电波变得快了一点，大脑活跃些。

而大的缓
波和睡得最深是 stage 4 sleep的特征，rapid for the first few minutes是stage 1 sleep的特征，整个睡眠阶段都是有脑电波的，故A，B和C皆错。

感谢您的阅读，祝您生活愉快。