全国硕士硕士入学统一考试英语试题SectionⅠUseofEnglishSleepisdividedintoperiodsofso-calledREMsleep,characterizedbyrapideyemovementsanddreaming,andlongerperiodsofnon-REMsleep
1kindofsleepisatallwell-understood,butREMsleepis2toservesomerestorativefunctionofthebrain
Thepurposeofnon-REMsleepisevenmore3
Thenewexperiments,suchasthese4forthefirsttimeatarecentmeetingoftheSocietyforSleepResearchinMinneapolis,suggestfascinatingexplanations5ofnon-REMsleep
Forexample,ithaslongbeenknownthattotalsleep6is100percentfataltorats,yet,7_examinationsofthedeadbodies,theanimalslookcompletelynormal
Aresearcherhasnow8themysteryofwhytheanimalsdie
Therats9bacterialinfectionsoftheblood,10theirimmunesystems—theself-protectingmechanisrnagainstdisease—hadcrashed
[A]Either[B]Neither[C]Each[D]Any2
[A]intended[B]required[C]assumed[D]infer