北美新托福入学测试题中上水平.docx

北美新托福入学测试题中上水平.docx

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北美新托福入学测试题中上水平

环球新托福考试院入学英语水平测试题

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ExtinctionoftheDinosaurs

Paleontologistshavearguedforalongtimethatthedemiseofthedinosaurswascausedbyclimaticalterationsassociatedwithslowchangesinthepositionsofcontinentsandseasresultingfromplatetectonics.OffandonthroughouttheCretaceous（thelastperiodoftheMesozoicera,duringwhich

/\dinosaursflourished）,largeshallowseascoveredextensiveareasofthecontinents.Datafromdiversesources,includinggeochemicalevideneepreservedinseafloorsediments,indicatethattheLate

Cretaceousclimatewasmilderthantoday's.Thedayswerenottoohot,northenightstoocold.The

summerswerenottoowarm,northewinterstoofrigid.Theshallowseasonthecontinentsprobablybufferedthetemperatureofthenearbyair,keepingitrelativelyconstant.

AttheendoftheCretaceous,thegeologicalrecordshowsthattheseseawaysretreatedfromthecontinentsbackintothemajoroceanbasins.Nooneknowswhy.Overaperiodofabout100,000years,whiletheseaspulledback,climatesaroundtheworldbecamedramaticallymoreextreme:

warmerdays,coolernights;hottersummers,colderwinters.Perhapsdinosaurscouldnottoleratetheseextreme

temperaturechangesandbecameextinct.

were

shardtounderstandwhytweyldnotbeaffected,whereas

dinosaurswerelefttoocrippledtocope,especiallyif,assomescientistsbelieve,dinosaurs

warm-blooded.CriticsalsopointoutthattheshallowseawayshadretreatedfromandadvaneedonthecontinentsnumeroustimesduringtheMesozoic,sowhydidthedinosaurssurvivetheclimaticchanges

appealing,the

associatedwiththeearlierfluctuationsbutnotwiththisone?

Althoughinitiallyhypothesisofasimpleclimaticchangerelatedtosealevelsisinsufficienttoexplainallthedata.

Dissatisfactionwithconventionalexplanationsfordinosaurextinctionsled/toasurprising

observationthat,inturn,hassuggestedanewhypothesis.Manyplantsandanimalsdisappear

abruptlyfromthefossilrecordasonemovesfromlayersofrockdocumentingtheendoftheCretaceousupintorocksrepresentingthebeginningoftheCenozoic（theeraaftertheMesozoic）.BetweenthelastlayerofCretaceousrockandthefirstlayerofCenozoicrock,thereisoftenathinlayerofclay.Scientistsfeltthattheycouldgetanideaofhowlongtheextinctionstookbydetermininghowlongittooktodepositthisonecentimeterofclayandtheythoughttheycoulddeterminethetimeittooktodeposittheclaybydeterminingtheamountoftheelementiridium（lr）itcontained.

shistory.Becaus，

'scoreasth

IthasnotbeencommonatEarth'ssincetheverybeginningoftheplanet

usuallyexistsinametallicstate,itwaspreferentiallyincorporatedinEarthandconsolidated.ltisfoundinhighconcentrationsinsomemeteorites,inwhichthesolarsystem

originalchemicalcompositionispreserved.Eventoday,microscopicmeteoritescontinuallybombardEarth,fallingonbothlandandsea.BymeasuringhowmanyofthesemeteoritesfalltoEarthoveragivenperiodoftime,scientistscanestimatehowlongitmighthavetakentodeposittheobserved

amountofitintheboundaryclay.Thesecalculationssuggestthataperiodofaboutonemillionyears

wouldhavebeenrequired.However,otherreliableevideneesuggeststhatthedepositionofthe

boundaryclaycouldnothavetakenonemillionyears.Sotheunusuallyhighconcentrationofltseems

torequireaspecialexplanation.

Inviewofthesefacts,scientistshypothesizedthatasinglelargeasteroid,about10to15kilometers

across,collidedwithEarth,andtheresultingfalloutcreatedtheboundaryclay.Theircalculations

showthattheimpactkickedupadustcloudthatcutoffsunlightforseveralmonths,inhibiting

photosynthesisinplants;decreasedsurfacetemperaturesoncontinentstobelowfreezing;caused

extremeepisodesofacidrain;andsignificantlyraisedIong-termglobaltemperaturesthroughthe

greenhouseeffect.Thisdisruptionoffoodchainandclimatewouldhaveeradicatedthedinosaursand

otherorganismsinlessthanfiftyyears.

[PassageEnd]

[Question]

Paragraph1Paleontologistshavearguedforalongtimethatthedemiseofthedinosaurswas

causedbyclimaticalterationsassociatedwithslowchangesinthepositionsofcontinentsandseas

resultingfromplatetectonics.OffandonthroughouttheCretaceous（thelastperiodoftheMesozoicera,duringwhichdinosaursflourished）,largeshallowseascoveredextensiveareasofthecontinents.Datafromdiversesources,includinggeochemicalevideneepreservedinseafloorsediments,indicatethatthe

LateCretaceousclimatewasmilderthantoday's.Thedayswerenottoohot,northenightstoocold.

Thesummerswerenottoowarm,northewinterstoofrigid.Theshallowseasonthecontinentsprobablybufferedthetemperatureofthenearbyair,keepingitrelativelyconstant.

1.Accordingtoparagraph1,whichofthefollowingistrueoftheLateCretaceousclimate?

Summerswereverywarmandwinterswereverycold.

Shallowseasonthecontinentscausedfrequenttemperaturechanges.

Theclimatewasverysimilartotoday'sclimate.

Theclimatedidnotchangedramaticallyfromseasontoseason.

Paragraph2AttheendoftheCretaceous,thegeologicalrecordshowsthattheseseawaysretreated

fromthecontinentsbackintothemajoroceanbasins.Nooneknowswhy.Overaperiodofabout100,000years,whiletheseaspulledback,climatesaroundtheworldbecamedramaticallymoreextreme:

warmerdays,coolernights;hottersummers,colderwinters.Perhapsdinosaurscouldnot

toleratetheseextremetemperaturechangesandbecameextinct.

2.Whichofthefollowingreasonsissuggestedinparagraph2fortheextinctionofthedinosaurs?

ChangesinthelengthsofthedaysandnightsduringthelateCretaceousperiod

Droughtscausedbythemovementofseawaysbackintotheoceans

ThechangefrommildtosevereclimatesduringtheLateCretaceousperiod

Anextremedecreaseintheaverageyearlytemperatureover10,000years

Paragraph3Iftrue,though,whydidcold-bloodedanimalssuchassnakes,lizards,turtles,and

crocodilessurvivethefreezingwintersandtorridsummers?

Theseanimalsareatthemercyofthe

climatetomaintainalivablebodytemperature.It'shardtounderstandwhytheywouldnotbe

affected,whereasdinosaurswerelefttoocrippledtocope,especiallyif,assomescientistsbelieve,

dinosaurswerewarm-blooded.CriticsalsopointoutthattheshallowseawayshadretreatedfromandadvaneedonthecontinentsnumeroustimesduringtheMesozoic,sowhydidthedinosaurssurvivetheclimaticchangesassociatedwiththeearlierfluctuationsbutnotwiththisone?

Althoughinitially

appealing,thehypothesisofasimpleclimaticchangerelatedtosealevelsisinsufficienttoexplainallthedata.

3.Whydoestheauthormentionthesurvivalof“snakes,lizards,turtles,andcrocodiles”n

paragraph3?

Toarguethatdinosaursmayhavebecomeextinetbecausetheywerenotcold-bloodedanimals

Toquestiontheadequacyofthehypothesisthatclimaticchangerelatedtosealevelscausedthe

extinctionofthedinosaurs

Topresentexamplesofanimalsthatcouldmaintainalivablebodytemperaturemoreeasilythan

dinosaurs

Tosupportahypothesisthattheseanimalswerenotassensitivetoclimatechangesinthe

Cretaceousperiodastheyaretoday

4.Thewordcopeinthepassageisclosestinmeaningto

adapt

move

continue

compete

5.Thewordfluctuationsinthepassageisclosestinmeaningto

extremes

retreatsperiodsvariations

Paragraph4Dissatisfactionwithconventionalexplanationsfordinosaurextinctionsledtoa

surprisingobservationthat,inturn,hassuggestedanewhypothesis.Manyplantsandanimals

disappearabruptlyfromthefossilrecordasonemovesfromlayersofrockdocumentingtheendoftheCretaceousupintorocksrepresentingthebeginningoftheCenozoic（theeraaftertheMesozoic）.BetweenthelastlayerofCretaceousrockandthefirstlayerofCenozoicrock,thereisoftenathinlayerofclay.Scientistsfeltthattheycouldgetanideaofhowlongtheextinctionstookbydetermininghowlongittooktodepositthisonecentimeterofclayandtheythoughttheycoulddeterminethetimeittooktodeposittheclaybydeterminingtheamountoftheelementiridiumitcontained.

6.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlighted

sentenceinthepassage?

Incorrectchoiceschangethemeaninginimportantwaysorleaveout

essentialinformation.

Thefossilrecordsuggeststhattherewasanabruptextinctionofmanyplantsandanimalsatthe

endoftheMesozoicera.

FewfossilsoftheMesozoicerahavesurvivedintherocksthatmarktheendoftheCretaceous.

FossilsfromtheCretaceousperiodoftheMesozoicuptothebeginningoftheCenozoicerahave

beenremovedfromthelayersofrockthatsurroundedthem.

PlantsandanimalsfromtheMesozoicerawereunabletosurviveintheCenozoicera.

7.Inparagraph4,allthefollowingquestionsareansweredEXCEPT:

WhyistherealayerofclaybetweentherocksoftheCretaceousandCenozoic?

Whywerescientistsinterestedindetermininghowlongittooktodepositthelayerofclayattheend

oftheCretaceous?

Whatwastheeffectofthesurprisingobservationscientistsmade?

Whydidscientistswantmoreinformationaboutthedinosaurextinctionsattheendofthe

Cretaceous?

Paragraph5.lthasnotbeencommonatEarth'ssincetheverybeginningoftheplanet's

Because