TOEFL閱讀真題精選

TOEFL閱讀真題精選為了讓大家更好的準備托?？荚嚕o大家整理一些托福閱讀真題，下面就和大家分享，來欣賞一下吧。托福閱讀真題iThereareonlyafewcluesintherockrecordaboutclimateintheProterozoiceon.Muchofourinformationaboutclimateinthemorerecentperiodsofgeologichistorycomesfromthefossilrecord,becausewehaveareasonablygoodunderstandingofthetypesofenvironmentinwhichmanyfossilorganismsflourished.ThescarcefossilsoftheProterozoic,mostlysingle-celledbacteria,providelittleevidenceinthisregard.However,therocksthemselvesdoincludetheearliestevidenceforglaciation,probablyaglobaliceage.Theinferencethatsometypesofsedimentaryrocksaretheresultofglacialactivityisbasedontheprincipleofuniformitarianism,whichpositsthatnaturalprocessesnowatworkonandwithintheEarthoperatedinthesamemannerinthedistantpast.Thedepositsassociatedwithpresent-dayglaciershavebeenwellstudied,andsomeoftheircharacteristicsarequitedistinctive.In2.3-billion-year-oldrocksinCanadanearLakeHuron(datingfromtheearlypartoftheProterozoicage),therearethinlaminaeoffine-grainedsedimentsthatresemblevarves,theannuallayersofsedimentdepositedinglaciallakes.Typically,present-dayvarvesshowtwo-layeredannualcycle,onelayercorrespondingtotherapidicemeltingandsedimenttransportofthesummerseason,andtheother,finer-grained,layercorrespondingtoslowerwinterdeposition.AlthoughitisnoteasytodiscernsuchdetailsintheProterozoicexamples,theyarealmostcertainlyglacialvarves.Thesefine-grained,layeredsedimentsevencontainoccasionallargepebblesordropstones,acharacteristicfeatureofglacialenvironmentswherecoarsematerialissometimescarriedonfloatingiceanddroppedfarfromitssource,intootherwiseveryfinegrainedsediment.GlacialsedimentsofaboutthesameageasthoseinCanadahavebeenfoundinotherpartsofNorthAmericaandinAfrica,India,andEurope.Thisindicatesthattheglaciationwasglobal,andthatforaperiodoftimeintheearlyProterozoictheEarthwasgrippedinaniceage.FollowingtheearlyProterozoicglaciation,however,theclimateappearstohavebeenfairlybenignforaverylongtime.Thereisnoevidenceforglaciationforthenext1.5billionyearsorso.Then,suddenly,therockrecordindicatesaseriesofglacialepisodesbetweenabout850and600millionyearago,neartheendoftheProterozoiceon.Whichofthefollowingdoesthepassagemainlydiscuss?HowpatternsinrocklayershavebeenusedtoconstructtheoriesabouttheclimateoftheProterozoicageWhatsomerarefossilsindicateaboutglacialconditionsduringthelateProterozoicageThevaryingcharacteristicsofProterozoicglacialvarvesindifferentpartsoftheworldThenumberofglacialepisodesthattheEarthhasexperiencedsincetheProterozoicageAccordingtothepassage,thefossilrecordoftheProterozoiceonishighlyregardedbecauseitpreservestheremainsofmanykindsoforganismslessinformativethanthefossilrecordofmorerecentperiodsverydifficulttointerpretduetodamagefrombacteriamoreusefultoresearchersthanotheraspectsoftherockrecordThewordscarceinline4isclosestinmeaningtoancienttinyavailablerareItcanbeinferredfromthepassagethattheprincipleofuniformitarianismindicatessimilarconditionsproducesimilarrockformationsrocklayersinagivenregionremainundisturbedovertimedifferentkindsofsedimentaryrocksmayhavesimilaroriginseachcontinenthasitsowndistinctivepatternofsedimentlayersThewordresembleinline14isclosestinmeaningtoresultfrompenetratelooklikereplacehavesimilaroriginsAccordingtothepassage,thelayersinvarvesareprimarilyformedbyfossilizedbacteriapiecesofancientdropstonesacombinationofancientandrecentsedimentsannualcyclesofsedimenttransportanddepositionThephrasetheotherinline17referstoanotherannualcycleglaciallakelayerofsedimentseasonAccordingtothepassage,thepresenceofdropstonesindicatesthattheglacialenvironmenthasbeenunusuallyserverethefine-grainedsedimenthasbuiltupveryslowlytherehasbeenaglobaliceagecoarserockmaterialhasbeencarriedgreatdistancesWhydoestheauthormentionCanada,NorthAmerica,Africa,India,andEuropeinlines23-24?TodemonstratetheglobalspreadofdropstonesToexplaintheprinciplesofvarveformationToprovideevidenceforthetheorythattherewasaglobaliceageintheearlyProterozoiceonToillustratethevariedclimaticchangesoftheProterozoiceonindifferentpartsoftheglobeWhichofthefollowingtermsisdefinedinthepassage?fossilrecord(line3)laminae(line13)varves(line14)glacialepisodes(line28)PASSAGE92ABDACDCCCC托福閱讀真題2In1900theUnitedStateshadonlythreecitieswithmorethanamillionresidents—NewYork,Chicago,andPhiladelphia.By1930,ithadtengiantmetropolises.Theneweronesexperiencedremarkablegrowth,whichreflectedbasicchangesintheeconomy.ThepopulationofLosAngeles(114,000in1900)rosespectacularlyintheearlydecadesofthetwentiethcentury,increasingadramatic1,400percentfrom1900to1930.AnumberofcircumstancescontributedtothemeteoricriseofLosAngeles.Theagriculturalpotentialoftheareawasenormousifwaterforirrigationcouldbefound,andthecityfoundershadthevisionanddatingtoobtainitbyconstructinga225-mileaqueduct,completedin1913,totapthewateroftheOwensRiver.Thecityhadasuperbnaturalharbor,aswellasexcellentrailconnections.Theclimatemadeitpossibletoshootmotionpicturesyear-round;henceHollywood.Hollywoodnotonlysuppliedjobs;itdisseminatedanimageofthegoodlifeinSouthernCaliforniaonscreensallacrossthenation.ThemostimportantsingleindustrypoweringthegrowthofLosAngeles,however,wasdirectlylinkedtotheautomobile.ThedemandforpetroleumtofuelgasolineenginesledtotheopeningoftheSouthernCaliforniaoilfields,andmadeLosAngelesNorthAmericasgreatestrefiningcenter.LosAngeleswasaproductoftheautoageinanothersenseaswell:itsdistinctivespatialorganizationdependedonwidespreadprivateownershipofautomobiles.LosAngeleswasadecentralizedmetropolis,sprawlingacrossthedesertlandscapeoveranareaof400squaremiles.Itwasacitywithoutarealcenter.Thedowntownbusinessdistrictdidnotgrowapacewiththecityasawhole,andtherapidtransitsystemdesignedtolinkthecenterwithoutlyingareaswitheredawayfromdisuse.Approximately800,000carswereregisteredinLosAngelesCountyin1930,oneper2.7residents.Somevisitorsfromtheeastcoastweredismayedattheendlessurbansprawlanddismis