翻译文章：sleepSleep Sleep is part of a person’s daily activity c

翻译文章：sleep
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 sleeper, your sleep cycle is as follows. When you fist drift off into slumber, 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 consciousness you will have reached the deepest sleep of all. Your brain 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 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.

睡眠
睡眠是人的日常活动周期的一部分.有几个不同的睡眠阶段,它们是周期性出现的.如果你是个普通睡眠者,你的睡眠周期如下：刚刚进入微睡阶段,你的眼睛会稍微转动,体温稍降,肌肉放松,呼吸放慢并且很有节奏.脑波减速 也变得很有规律性.随着快波睡眠1期第一节奏,你的脑波也稍稍减速.接下来大约半小时左右,当你越来越放松,你会进入二期和三期睡眠.睡眠的阶段越低,脑波的速度越慢.大约40----69分钟后,当你失去意识,你会进入深度睡眠.你的大脑会显示出最大的慢波,这就是我们常说的δ波.这是睡眠的第四阶段.
你并非整夜都处于这第四深度睡眠阶段,而是在你入睡约80分钟后,你的大脑活动水平会再度稍微提高,δ波消失,代为出现的是脑波的活动波型.你的眼睛在紧闭的眼皮底下转动,好象在看 眼前发生的景象.这一眼球快速运动的睡眠阶段大约持续8到15分钟,被称为快速眼动睡眠.在快速眼动睡眠阶段,你的身体会再度放松,呼吸会轻微地再次重复第一至第四阶段睡眠状态,大约80分钟后,当你再次再次起身,会达到接近意识清醒水平.