GMAT 2016版OG Reading Comprehension新题

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1、LineScientistslongbelievedthattwonerveclustersinthehumanhypothalamus,calledsuperchiasmaticnuclei(SCNs),werewhatcontrolledourcircadianrhythms.Thoserhythmsarethebiologicalcycles(5)thatrecurapproximatelyevery24hoursinsynchronizationwiththecycleofsunlightanddarknesscausedbyEarth’srotation.Studieshavede

2、monstratedthatinsomeanimals,theSCNscontroldailyfluctuationsinbloodpressure,body(10)temperature,activitylevel,andalertness,aswellasthenighttimereleaseofthesleep-promotingagentmelatonin.Furthermore,cellsinthehumanretinadedicatedtotransmittinginformationaboutlightlevelstotheSCNshaverecentlybeendiscove

3、red.(15)Fourcriticalgenesgoverningcircadiancycleshavebeenfoundtobeactiveineverytissue,however,notjusttheSCNs,offiles,mice,andhumans.Inaddition,whenlaboratoryratsthatusuallyateatwillwerefedonlyonceaday,peak(20)activityofaclockgeneintheirliversshiftedby12hours,whereasthesameclockgeneintheSCNsremained

4、synchronizedwithlightcycles.WhilescientistsdonotdisputetheroleoftheSCNsincontrollingcorefunctionssuchastheregulationof(25)bodytemperatureandbloodpressure,scientistsnowbelievethatcircadianclocksinotherorgansandtissuesmayrespondtoexternalcuesotherthanlight—includingtemperaturechanges—thatrecurregular

5、lyevery24hours.Questions8-10refertothepassage.8.Theprimarypurposeofthepassageisto(A)challengerecentfindingsthatappeartocontradictearlierfindings(B)presenttwosidesofanongoingscientificdebate(C)reportanswerstoseveralquestionsthathavelongpuzzledresearchers(D)discussevidencethathascausedalong-standingb

6、elieftoberevised(E)attempttoexplainacommonlymisunderstoodbiologicalphenomenon9.ThepassagementionseachofthefollowingasafunctionregulatedbytheSCNsinsomeanimalsEXCEPT(A)activitylevel(B)bloodpressure(C)alertness(D)vision(E)temperature10.Theauthorofthepassagewouldprobablyagreewithwhichofthefollowingstat

7、ementsabouttheSCNs?(A)TheSCNsarefoundinotherorgansandtissuesofthebodybesidesthehypothalamus.(B)TheSCNsplayacriticalbutnotexclusiveroleinregulatingcircadianrhythms.(C)TheSCNscontrolclockgenesinanumberoftissu