新东方背诵文选 L49 Sleep

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 sleeper¹, your sleep cycle is as follows. When you fist drift off into slumber², your eyes will roll about a bit, you temperature will drop slightly, your muscles will relax, and your breathing well slow and become quite regular. Your brain waves slow and become quite regular. Your brain waves slow down a bit too, with the alpha rhythm of rather fast waves 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. slower your brain waves will be. Then about 40to 69 minutes after you lose consciousness³ you will have reached the deepest sleep of all. Your brain will show the large slow waves that are known as the delta⁴ 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 dart⁵ around under your closed eyelids⁶ 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 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.
 

1 sleeper   

n.睡眠者，卧车，卧铺

参考例句：

• I usually go up to London on the sleeper. 我一般都乘卧车去伦敦。
• But first he explained that he was a very heavy sleeper. 但首先他解释说自己睡觉很沉。

2 slumber   

n.睡眠，沉睡状态

参考例句：

• All the people in the hotels were wrapped in deep slumber.住在各旅馆里的人都已进入梦乡。
• Don't wake him from his slumber because he needs the rest.不要把他从睡眠中唤醒，因为他需要休息。

3 consciousness   

n.意识，觉悟，知觉

参考例句：

• The experience helped to change her social consciousness.这种经验有助于改变她的社会意识。
• He lost consciousness at the first whiff of ether.他一嗅到乙醚便失去了知觉。

4 delta   

n.（流的）角洲

参考例句：

• He has been to the delta of the Nile.他曾去过尼罗河三角洲。
• The Nile divides at its mouth and forms a delta.尼罗河在河口分岔，形成了一个三角洲。

5 dart   

v.猛冲，投掷；n.飞镖，猛冲

参考例句：

• The child made a sudden dart across the road.那小孩突然冲过马路。
• Markov died after being struck by a poison dart.马尔科夫身中毒镖而亡。

6 eyelids   

n.眼睑( eyelid的名词复数 )；眼睛也不眨一下；不露声色；面不改色

参考例句：

• She was so tired, her eyelids were beginning to droop. 她太疲倦了，眼睑开始往下垂。
• Her eyelids drooped as if she were on the verge of sleep. 她眼睑低垂好像快要睡着的样子。 来自《简明英汉词典》