托福阅读模拟试题及答案卷四.docx

托福阅读模拟试题及答案卷四.docx

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托福阅读模拟试题及答案卷四

2020年托福阅读模拟试题及答案（卷四）

　托福阅读文本：

　　Scientistshavediscoveredthatforthelast160,000years,atleast,therehasbeenaconsistent

　　relationshipbetweentheamountofcarbondioxideintheairandtheaveragetemperatureofthe

　　planet.TheimportanceofcarbondioxideinregulatingtheEarth'stemperaturewasconfirmedby

　　scientistsworkingineasternAntarctica.Drillingdownintoaglacier,theyextractedamile-long

　　cylinderoficefromthehole.Theglacierhadformedaslayeruponlayerofsnowaccumulated

　　yearafteryear.Thusdrillingintotheicewastantamounttodrillingbackthroughtime.

　　Thedeepestsectionsofthecorearecomposedofwaterthatfellassnow160,000yearsago.

　　ScientistsinGrenoble,France,fracturedportionsofthecoreandmeasuredthecompositionof

　　ancientairreleasedfrombubblesintheice.Instrumentswereusedtomeasuretheratioofcertain

　　isotopesinthefrozenwatertogetanideaoftheprevailingatmospherictemperatureatthetime

　　whenthatparticularbitofwaterbecamelockedintheglacier.

　　Theresultisaremarkableunbrokenrecordoftemperatureandofatmosphericlevelsofcarbon

　　dioxide.Almosteverytimethechillofaniceagedescendedontheplanet,carbondioxidelevels

　　dropped.Whentheglobaltemperaturedropped9°F（5°C）,carbondioxidelevelsdroppedto190

　　partspermillionorso.Generally,aseachiceageendedandtheEarthbaskedinawarm

　　interglacialperiod,carbondioxidelevelswerearound280partspermillion.Throughthe160,000

　　yearsofthaticerecord,thelevelofcarbondioxideintheatmospherefluctuatedbetween190and

　　280partspermillion,butneverrosemuchhigher-untiltheIndustrialRevolutionbeginninginthe

　　eighteenthcenturyandcontinuingtoday.

　　Thereisindirectevidencethatthelinkbetweencarbondioxidelevelsandglobaltemperature

　　changegoesbackmuchfurtherthantheglacialrecord.Carbondioxidelevelsmayhavebeen

　　muchgreaterthanthecurrentconcentrationduringtheCarboniferousperiod,360to285million

　　yearsago.Theperiodwasnamedforaprofusionofplantlifewhoseburiedremainsproduceda

　　largefractionofthecoaldepositsthatarebeingbroughttothesurfaceandburnedtoday.

　　托福阅读题目：

　　1.Whichofthefollowingdoesthepassagemainlydiscuss?

　　（A）Chemicalcausesoficeages

　　（B）Techniquesforstudyingancientlayersoficeinglaciers

　　（C）Evidenceofarelationshipbetweenlevelsofcarbondioxideandglobaltemperature

　　（D）Effectsofplantlifeoncarbondioxidelevelsintheatmosphere

　　2.Theword"accumulated"inline6isclosestinmeaningto.

　　（A）spreadout

　　（B）changed

　　（C）becamedenser

　　（D）builtup

　　3.Accordingtothepassage,thedrillingoftheglacierineasternAntarcticawasimportantbecause

　　it

　　（A）allowedscientiststoexperimentwithnewdrillingtechniques

　　（B）permittedthestudyofsurfacetemperaturesinanice-coveredregionofEarth

　　（C）providedinsightaboutclimateconditionsinearlierperiods

　　（D）confirmedearlierfindingsabouthowglaciersareformed

　　4.Thephrase"tantamountto"inline7isclosestinmeaningto

　　（A）complementaryto

　　（B）practicallythesameas

　　（C）especiallywellsuitedto

　　（D）unlikelytobeconfusedwith

　　5.Accordingtothepassage,Grenoble,France,istheplacewhere

　　（A）instrumentsweredevelopedformeasuringcertainchemicalelements

　　（B）scientistsfirstrecordedatmosphericlevelsofcarbondioxide

　　（C）scientistsstudiedthecontentsofanicecorefromAntarctica

　　（D）therelationshipbetweencarbondioxideandtemperaturewasdiscovered

　　6.Accordingtothepassage,scientistsusedisotopesfromthewateroftheicecoretodetermine

　　whichoffollowing?

　　（A）Theamountofairthathadbubbledtothesurfacesincetheicehadformed

　　（B）Thetemperatureoftheatmospherewhentheicewasformed

　　（C）Thedateatwhichwaterhadbecomelockedintheglacier

　　（D）Therateatwhichwaterhadbeenfrozenintheglacier

　　7.Theword"remarkable"inline14isclosestinmeaningto

　　（A）genuine

　　（B）permanent

　　（C）extraordinary

　　（D）continuous

　　8.Theword"link"inline23isclosestinmeaningto

　　（A）tension

　　（B）connection

　　（C）attraction

　　（D）distance

　　9.Thepassageimpliesthatthewarmesttemperaturesamongtheperiodsmentionedoccurred

　　（A）intheearlyeighteenthcentury

　　（B）160,000yearsago

　　（C）attheendofeachiceage

　　（D）between360and285millionyearsago

　　10.Accordingtothepassage,theCarboniferousperiodwascharacterizedby

　　（A）areductioninthenumberofcoaldeposits

　　（B）theburningofalargeamountofcoal

　　（C）anabundanceofplants

　　（D）anacceleratedrateofglacierformation

　　11.Thepassageexplainstheoriginofwhichofthefollowingterms?

　　（A）glacier（line5）

　　（B）isotopes（li