六级阅读第三十七天(加强卷)完整版

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1、Passage★★★☆☆Questions1to5arebasedonthefollowingpassage.AnimagetakenofthePacificOceanlastSeptemberisastonishing.MadeusingdatacollectedfromsatellitesmonitoredbyNASA'sJetPropulsionLaboratoryinPasadena,California,thepictureshowsthesurfacelevelofthePacificasclearlyasayardsticklyingacrossalumpy

2、bed.Onesampleofwater--withavolume30timesthatofalltheGreatLakes--iswhite,indicatingthatitisasmuchas13incheshigherthanitsnormallevel.ElNinoexpertsarestillstrivingtotacklethereallybigquestion:whatiscausingtheabnormalElNinobehaviorofthepasttwodecades?Somesaidbecauseglobalwarmingacceleratesthe

3、paceofElNinoformationandreinforceseachevent.SupportersofglobalwarmingasElNinoinstigatorincludeKevinTrenberth,aclimateanalystwiththeNationalCenterforAtmosphericResearchinBoulder,Colorado."There'sevidencethatglobalwarmingdidn'thavemuchimpactuntil1979,butnowit'sbeginningtobreakthrough,"hesay

4、s.Twoadditionalargumentsareonthetable.OnetheoryisthattherecentElNinoepidemicissimplyoneofnature'sclimatictiffs,butthatwehaven'tbeenheatingthetunelongenoughtorecognizethechangeinkey.OneproblemisthathistoricaldataonElNinoissketchypriortotheearly1970sandalmostnonexistentgoingbackmorethan50ye

5、ars.Ifonelooksbackfurther,however,fossilevidencesuggeststhatsomethingaboutElNinohasindeedchanged.FossilrecordsofcoralintheGalapagosIslandsshowthatsome4,000yearsago,anElNinooccurredonlyevery60yearsorso.Studiesoftreeringsandicecoresindicateamorerecentcycleofsevenyears,stillmuchlessfrequentt

6、hanthepresentcycleofeverythreeorfouryears.Recordsareaccurateenoughtoshowthatwe'reinthesecondElNinointensiveeraofthepast100years.Thefirstwasduringthe1920sand30s,andprobablywasresponsiblefortheDustBowl,whendroughtdestroyedhundredsoffarmsinOklahomaandnorthTexas.Thesecondseemstohavestartedaro

7、und1976.TheseshiftsseemtobeduetoperiodsofnaturalwarminginthePacific.ThewarmingdoesnotnecessarilycauseElNinobutcertainlyamplifiesit,creatingtheappearanceofmoreandmoresevereElNinos.1.Thepictureasdepictedbytheauthorinthefirstparagraphseemstobe______.[A].fairlyreassurin