【考研真题】1995年完型

英语自学网

Hints：
        REM
        non-REM
        Society for Sleep Research
        Minneapolis
        文中有4处连字符，一处破折号。
       
Sleep is divided into periods of so-called REM sleep, characterized by rapid eye movements and dreaming, and longer periods of non-REM sleep. Neither kind of sleep is at all well understood, but REM sleep is assumed to serve some restorative function of the brain. The purpose of non-REM sleep is even more mysterious. The new experiments, such as these described for the first time at a recent meeting of the Society for Sleep Research in Minneapolis, suggest fascinating explanations for the purpose of non-REM sleep.
For example, it has long been known that total sleep deprivation is 100% fatal to rats, yet, upon examination of the dead bodies, the animals look completely normal. A researcher has now cast light on the mystery of why the animals die. The rats develop bacterial infections of the blood, as if their immune systems -- the self-protecting mechanism against disease -- had crashed.睡眠通常被分为所谓的快动眼睡眠阶段和较长的非快动眼睡眠。前者的特点为眼球快速的转动并伴有做梦。我们对两种形式的睡眠了解都不多，但是人们假设REM睡眠对大脑起着某种康复功能。非快动眼睡眠起的作用更为神秘。最近睡眠研究协会在明尼阿波利斯举行的会议上，专家们首次描述的一些新实验，对眼球非快速移动睡眠的作用的阐述令人着迷。
比如，人们早已了解到，完全剥夺老鼠的睡眠对其具有100%的致命性，然而，在检查老鼠死尸时，这些动物看上去完全正常。一位研究人员已阐明了这些动物死亡原因的奥秘。老鼠患上了血液细菌感染，似乎他们的免疫系统——抵御疾病的自我保护机制——已崩溃。