1.Whichofthefollowingbestdescribesthefunctionofthehighlightedsentence?

A.Itrefutesthepossibilityofaconnectionbetweentwoeventspreviouslythoughttoberelated.

B.Itdescribeshowahypothesismightaccountforthetimingofaphenomenondescribedearlierinthepassage

C.Itpresentsevidencethatcastsdoubtonastatementmadeinthefirstsentenceofthepassage

D.Itclarifiesadistinctionbetweentworelatedhypotheses

E.Itintroducesfindingsthatchallengeadominantexplanationforaparticularphenomenon

2.Whichofthefollowingcanbeinferredfromthepassageaboutmethanogens?

A.MethanogensmusthaveappearedonEarthlaterthan2.3billionyearsago.

B.MethanogensmusthavebeenmuchmoreprevalentinsomeregionsoftheearlyEarththaninothers.

C.MethanogensproduceagreenhousegasthatismoresusceptibletodestructionbytheSun’sultraviolentraysthanisammonia.

D.MethanogenscouldnothavethrivedinearlyEarth’satmospherewithoutthepresenceofammonia.

E.MethanogenswouldhavehadalesssignificanteffectonearlyEarth’satmosphereiftheyhadevolvedaftertheappearanceofcyanobacteria.

答案：BE

Passage24

Someresearchersclaimthatcetaceans—whalesanddolphins—haveculture,whichtheresearchersdefineastheabilitytolearnfromoneanother.Skeptics,however,demandclearevidencethatcetaceanscanacquirenewbehaviorsthroughsomeformofsociallearning,preferablyclear-cutinstancesofimitationorteaching.Butsuchevidenceisdifficulttoobtain.Whilefewpeopledoubtthatcaptivecetaceansareadeptatimitationorthattheyreproducebehaviorstaughtbyresearchers,biologistsseekinginsightintocetaceans’behaviorintheirnaturalhabitatsmustrelyondeductionratherthanexperiments.Ifmembersofaparticulargroupsharebehaviorsthatdonotresultfromgeneticinheritanceorenvironmentalvariation,thentheyhavealmostcertainlylearnedthembywatching,following,orlisteningtootheranimals.

1.Whichofthefollowingbestdescribethefunctionofthehighlightedsentence?

A.Itidentifiesafactorthatcomplicatesbiologists’abilitytodrawconclusionsaboutthebehaviorofcetaceansintheirnaturalenvironments.

B.Itillustratesthekindofdeductionmentionedinthepreceding

21sentence.

C.Itexplainswhyskepticshaveremainedunpersuadedbyevidencethathasbeenputforwardinsupportoftheclaimthatcetaceanshaveculture.

D.Itintroducesaclaimthatwouldbedismissedbybothsupportersandopponentsoftheviewthatcetaceanshaveculture.

E.Itnotesapreviouslyoverlookedfactorthatmightshedlightonthequestionofwhethercetaceanshaveculture.

2.Thepassagesuggestswhichofthefollowingaboutcaptivecetaceans?

A.Whethertheyareengagedinsociallearningisasubjectofdisagreementamongbiologists.

B.Theirabilitytoimitatenewbehaviorsismoreextensivethanthatofnoncaptivecetaceans.

C.Theyexhibitfewbehaviorsthathavenotalsobeenobservedincetaceansintheirnaturalhabitats.

D.Theyappeartoadoptnewbehaviorsmorequicklythannoncaptivecetaceans.

E.Theyexhibittendenciesthatsuggestacapacityforthekindofbehaviorthatqualifiesascultural.

答案：BE

Passage25

HotterandmoremassivethantheSun,starscalled“stragglers”arepuzzlingtoastronomersbecausesuchrapidlyburningstarswouldnotbeexpectedtopersistinancientstarclusters.Someresearchersbelievethatthetypicalbluestragglersformedwhentwoancient,lower-massstarscollideandmergeformmoremassive,hotterstar.PeterLeonardtheorizesalternativelythatinlowdensityglobularclusters,wheremergersbetweensinglestarsoccurtooinfrequentlytoaccountfortheobservedquantityofbluestragglers,thesestragglersarecreatedinsteadbyagroupofstars.Hesuggeststhatapairofstarsalreadyorbitingeachotherpresentsalargertargetforathirdstaroranotherpair.Oncethisnewgroupingforms,closeencountersbetweenthestarscouldpromptanytwotomergeasabluestraggler.Leonard’smodelpredictsthateachbluestragglerhasadistantorbitingcompanion—asappearstrueofmanybluestragglersintheM67clusteroftheMilkyWaygalaxy.

1.Thereferencetoa“largertarget”servesprimarilytosuggestwhyaA.bluestragglerwouldbemorelikelytocollideandmergewithanotherstarthanwouldbealower-massstar

B.pairofstarswouldbemorelikelytoencounterotherstarsthanwouldthetypicalbluestraggler

C.pairofstarswouldbemorelikelytointeractwithotherstarsthanwouldasinglestar

D.bluestragglerwouldbemorelikelytointeractwithapairofstars

22thanitwouldwithathirdstar

E.thirdstarwouldbemorelikelytoencounterapairthanitwouldtoencounterabluestraggler

2.Informationpresentedinthepassagesuggestswhichofthefollowingaboutbluestragglers?

A.TheyoriginatefromstarsthatarehotterandmoremassivethantheSun.

B.Theyareburningmorerapidlythanothertypesofstarsobservedinancientstarclusters.

C.Theyareolderthanmostothertypesofstarswithinthesamestarcluster.

D.Theyarelessnumerousinlow-densityglobularclustersthanarepairsofstars.

E.Theygenerallyoriginatefromtheoldeststarsamongthosefoundinancientstarclusters.

3.Thepassageciteswhichofthefollowingasevidenceunderminingthetheorypresentedinthesecondsentence?

A.Adiscrepancybetweenthenumberofmergersbetweensinglestarsincertainlow-densityglobularclustersandthatinotherlow-densityglobularclusters

B.Adiscrepancybetweentheheatandmassofbluestragglersformedbyonetypeofprocessandtheheatandmassofbluestragglersformedbyanothertypeofprocess

C.Adiscrepancybetweenthefrequencyofstarmergersinlow-densityglobularclustersandthoseinhigh-densityglobularclusters

D.Adiscrepancybetweentheamountofheatandmassofancientsinglestarsandthatofbluestragglers

E.Adiscrepancybetweenthenumberofmergersbetweensinglestarsincertainstarclustersandthenumberofbluestragglersinthoseclusters

答案：CBE

Passage26

Mostseismologistsassumethatfollowingamajorearthquakeanditsaftershocks,thefault(abreakinEarth’scrustwherepressurecantriggeranearthquake)willremainquietuntilstresseshavetimetorebuild,typicallyoverhundredsorthousandsofyears.Recentevidenceofsubtleinteractionsbetweenearthquakesmayoverturnthisassumption,however.Accordingtothestress-triggeringhypothesis,faultsareunexpectedlyresponsivetosubtlestressestheyacquireasneighboringfaultsshift.Ratherthansimplydissipating,stressrelievedduringanearthquaketravelsalongthefault,concentratinginsitesnearby;eventhesmallestadditionalstressesmaythentriggeranotherquakealongthefaultoronanearbyfault.Althoughscientistshavelongviewedsuchsubtleinteractionsasnonexistent,thehypothesishasexplainedthelocationandfrequencyofearthquakes

23followingseveraldestructivequakesinCalifornia,Japan,andTurkey.

1.Accordingtothepassage,whichofthefollowingisanassumptionthatmaybeinvalidatedbyrecentseismologicalevidence?

A.EarthquakesarecausedbystressesbuildingupinfaultswithinEarth’scrust.

B.Mostmajorearthquakescanbepredictedwithreasonableaccuracy.C.Faultsarehighlyresponsivetoevenminorstressesinneighboringfaults.

D.Mostmajorearthquakesarefollowedbypredictableaftershocks.E.Afaultthathasresultedinamajorearthquakebecomesquietforalongperiod.

Forthefollowingquestion,considereachofthechoicesseparatelyandselectallthatapply.

2.Thepassagesuggeststhatmostseismologistsbelievewhichofthefollowingaboutfaultstresses?

A.Theyaredissipatedwhentheyresultinanearthquake.B.Theyaretransferredbetweenneighboringfaults.

C.Theywillnotcauseamajorearthquakealongthesamefaultinthespaceofafewyears.

答案：EAC

Passage27

MacArthurandWilsonsuggestedthatthebiodiversityofanislandwillvaryindirectproportiontoafunctionoftheisland’ssize(i.e.,largerislandscansupportagreaternumberofspecies)andininverseproportiontoafunctionofitsdistancefromthemainland(i.e.,manyremoteislandswilltendtosupportfewerspecies).Reducedbiodiversityinanislandcontextislikelytorequiresignificantadaptationonthepartofcolonizinghumanpopulations.Evansarguesthatthislimitationmakesislandsideallaboratoriesforthestudyofhumanadaptationstothenaturalenvironment,whilstRenfrewandWagstaff,intheintroductiontotheirstudyofMelos,focusonthislimitationinbiodiversityasa“significantcharacteristicoftheislandecosystem.”Forhumancommunities,however,thislimitationmaypotentiallybeoffsetbyotherfactors.Thereducedbiodiversityofanislandecosystemappliesonlytoterrestrialresources:theresourcesoftheseawillbeasrichasonanyothercoastalarea,andmaybeequallyimportanttohumancommunities.AsmallislandsuchasMaltaorMelosallowsallcommunitiesdirectaccesstothesea,providinganimportantnutritional“safetynet,”aswellasanelementofdietarydiversity,whichmayactuallygiveislandcommunitiesanadvantageovertheirlandlockedcounterparts.Islandsmayalsohavespecificnonbiologicalresources(suchasobsidianonMelos),whichmaybeusedinexchangewithcommunitiesonotherislandsandadjacentmainlands.

1.Theprimarypurposeofthepassageisto

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