托福TPO8阅读真题Part2文本及题目答案.docx

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1、托福TPO8浏览真题Part2文本及题目答案托福TPO8浏览真题Part2文本及题目答案托福TPO是我们托福浏览的重要参考资料，为了方便大家备考，下面我给大家整理了托福TPO8浏览真题Part2文本及题目答案，希望大家喜欢。托福TPO8浏览真题Part2ExtinctionoftheDinosaursPaleozoicEra334to248millionyearsagoMesozoicEra245to65millionyearsago-TriassicPeriod-JurassicPeriod-CretaceousPeriodCenozoicEra65millionyearsagotothep

2、resentPaleontologistshavearguedforalongtimethatthedemiseofthedinosaurswascausedbyclimaticalterationsassociatedwithslowchangesinthepositionsofcontinentsandseasresultingfromplatetectonics.OffandonthroughouttheCretaceous(thelastperiodoftheMesozoicera,duringwhichdinosaursflourished),largeshallowseascove

3、redextensiveareasofthecontinents.Datafromdiversesources,includinggeochemicalevidencepreservedinseafloorsediments,indicatethattheLateCretaceousclimatewasmilderthantodays.Thedayswerenottoohot,northenightstoocold.Thesummerswerenottoowarm,northewinterstoofrigid.Theshallowseasonthecontinentsprobablybuffe

4、redthetemperatureofthenearbyair,keepingitrelativelyconstant.AttheendoftheCretaceous,thegeologicalrecordshowsthattheseseawaysretreatedfromthecontinentsbackintothemajoroceanbasins.Nooneknowswhy.Overaperiodofabout100,000years,whiletheseaspulledback,climatesaroundtheworldbecamedramaticallymoreextreme:wa

5、rmerdays,coolernights;hottersummers,colderwinters.Perhapsdinosaurscouldnottoleratetheseextremetemperaturechangesandbecameextinct.Iftrue,though,whydidcold-bloodedanimalssuchassnakes,lizards,turtles,andcrocodilessurvivethefreezingwintersandtorridsummers?Theseanimalsareatthemercyoftheclimatetomaintaina

6、livablebodytemperature.Itshardtounderstandwhytheywouldnotbeaffected,whereasdinosaurswerelefttoocrippledtocope,especiallyif,assomescientistsbelieve,dinosaurswerewarm-blooded.CriticsalsopointoutthattheshallowseawayshadretreatedfromandadvancedonthecontinentsnumeroustimesduringtheMesozoic,sowhydidthedin

7、osaurssurvivetheclimaticchangesassociatedwiththeearlierfluctuationsbutnotwiththisone?Althoughinitiallyappealing,thehypothesisofasimpleclimaticchangerelatedtosealevelsisinsufficienttoexplainallthedata.Dissatisfactionwithconventionalexplanationsfordinosaurextinctionsledtoasurprisingobservationthat,int

8、urn,hassuggestedanewhypothesis.ManyplantsandanimalsdisappearabruptlyfromthefossilrecordasonemovesfromlayersofrockdocumentingtheendoftheCretaceousupintorocksrepresentingthebeginningoftheCenozoic(theeraaftertheMesozoic).BetweenthelastlayerofCretaceousrockandthefirstlayerofCenozoicrock,thereisoftenathi

9、nlayerofclay.Scientistsfeltthattheycouldgetanideaofhowlongtheextinctionstookbydetermininghowlongittooktodepositthisonecentimeterofclayandtheythoughttheycoulddeterminethetimeittooktodeposittheclaybydeterminingtheamountoftheelementiridium(Ir)itcontained.IrhasnotbeencommonatEarthssincetheverybeginningo

10、ftheplanetshistory.Becauseitusuallyexistsinametallicstate,itwaspreferentiallyincorporatedinEarthscoreastheplanetcooledandconsolidated.Irisfoundinhighconcentrationsinsomemeteorites,inwhichthesolarsystemsoriginalchemicalcompositionispreserved.Eventoday,microscopicmeteoritescontinuallybombardEarth,fall

11、ingonbothlandandsea.BymeasuringhowmanyofthesemeteoritesfalltoEarthoveragivenperiodoftime,scientistscanestimatehowlongitmighthavetakentodeposittheobservedamountofIrintheboundaryclay.Thesecalculationssuggestthataperiodofaboutonemillionyearswouldhavebeenrequired.However,otherreliableevidencesuggeststha

12、tthedepositionoftheboundaryclaycouldnothavetakenonemillionyears.SotheunusuallyhighconcentrationofIrseemstorequireaspecialexplanation.Inviewofthesefacts,scientistshypothesizedthatasinglelargeasteroid,about10to15kilometersacross,collidedwithEarth,andtheresultingfalloutcreatedtheboundaryclay.Theircalcu

13、lationsshowthattheimpactkickedupadustcloudthatcutoffsunlightforseveralmonths,inhibitingphotosynthesisinplants;decreasedsurfacetemperaturesoncontinentstobelowfreezing;causedextremeepisodesofacidrain;andsignificantlyraisedlong-termglobaltemperaturesthroughthegreenhouseeffect.Thisdisruptionoffoodchaina

14、ndclimatewouldhaveeradicatedthedinosaursandotherorganismsinlessthanfiftyyears.Paragraph1:Paleontologistshavearguedforalongtimethatthedemiseofthedinosaurswascausedbyclimaticalterationsassociatedwithslowchangesinthepositionsofcontinentsandseasresultingfromplatetectonics.OffandonthroughouttheCretaceous

15、(thelastperiodoftheMesozoicera,duringwhichdinosaursflourished),largeshallowseascoveredextensiveareasofthecontinents.Datafromdiversesources,includinggeochemicalevidencepreservedinseafloorsediments,indicatethattheLateCretaceousclimatewasmilderthantodays.Thedayswerenottoohot,northenightstoocold.Thesumm

16、erswerenottoowarm,northewinterstoofrigid.Theshallowseasonthecontinentsprobablybufferedthetemperatureofthenearbyair,keepingitrelativelyconstant.托福TPO8浏览题目Part21.Accordingtoparagraph1,whichofthefollowingistrueoftheLateCretaceousclimate?Summerswereverywarmandwinterswereverycold.Shallowseasonthecontinen

17、tscausedfrequenttemperaturechanges.Theclimatewasverysimilartotodaysclimate.Theclimatedidnotchangedramaticallyfromseasontoseason.Paragraph2:AttheendoftheCretaceous,thegeologicalrecordshowsthattheseseawaysretreatedfromthecontinentsbackintothemajoroceanbasins.Nooneknowswhy.Overaperiodofabout100,000year

18、s,whiletheseaspulledback,climatesaroundtheworldbecamedramaticallymoreextreme:warmerdays,coolernights;hottersummers,colderwinters.Perhapsdinosaurscouldnottoleratetheseextremetemperaturechangesandbecameextinct.2.Whichofthefollowingreasonsissuggestedinparagraph2fortheextinctionofthedinosaurs?Changesint

19、helengthsofthedaysandnightsduringthelateCretaceousperiodDroughtscausedbythemovementofseawaysbackintotheoceansThechangefrommildtosevereclimatesduringtheLateCretaceousperiodAnextremedecreaseintheaverageyearlytemperatureover10,oooyearsParagraph3:Iftrue,though,whydidcold-bloodedanimalssuchassnakes,lizar

20、ds,turtles,andcrocodilessurvivethefreezingwintersandtorridsummers?Theseanimalsareatthemercyoftheclimatetomaintainalivablebodytemperature.Itshardtounderstandwhytheywouldnotbeaffected,whereasdinosaurswerelefttoocrippledtocope,especiallyif,assomescientistsbelieve,dinosaurswerewarm-blooded.Criticsalsopo

21、intoutthattheshallowseawayshadretreatedfromandadvancedonthecontinentsnumeroustimesduringtheMesozoic,sowhydidthedinosaurssurvivetheclimaticchangesassociatedwiththeearlierfluctuationsbutnotwiththisone?Althoughinitiallyappealing,thehypothesisofasimpleclimaticchangerelatedtosealevelsisinsufficienttoexpl

22、ainallthedata.3.Whydoestheauthormentionthesurvivalofsnakes,lizards,turtles,andcrocodilesinparagraph3?Toarguethatdinosaursmayhavebecomeextinctbecausetheywerenotcold-bloodedanimalsToquestiontheadequacyofthehypothesisthatclimaticchangerelatedtosealevelscausedtheextinctionofthedinosaursTopresentexamples

23、ofanimalsthatcouldmaintainalivablebodytemperaturemoreeasilythandinosaursTosupportahypothesisthattheseanimalswerenotassensitivetoclimatechangesintheCretaceousperiodastheyaretoday4.Thewordcopeinthepassageisclosestinmeaningtoadaptmovecontinuecompete5.Accordingtoparagraph3,whichofthefollowingistrueofcha

24、ngesinclimatebeforetheCretaceousperiodandtheeffectofthesechangesondinosaurs?ClimatechangesassociatedwiththemovementofseawaysbeforetheCretaceousperioddidnotcausedinosaurstobecomeextinct.ChangesinclimatebeforetheCretaceousperiodcausedseverefluctuationsinsealevel,resultingintheextinctionofthedinosaurs.

25、FrequentchangesinclimatebeforetheCretaceousperiodmadedinosaursbetterabletomaintainalivablebodytemperature.BeforetheCretaceousperiodtherewerefewchangesinclimate,anddinosaursflourished.6.ThewordfluctuationsinthepassageisclosestinmeaningtoextremesretreatsperiodsvariationsParagraph4:Dissatisfactionwithc

26、onventionalexplanationsfordinosaurextinctionsledtoasurprisingobservationthat,inturn,hassuggestedanewhypothesis.ManyplantsandanimalsdisappearabruptlyfromthefossilrecordasonemovesfromlayersofrockdocumentingtheendoftheCretaceousupintorocksrepresentingthebeginningoftheCenozoic(theeraaftertheMesozoic).Be

27、tweenthelastlayerofCretaceousrockandthefirstlayerofCenozoicrock,thereisoftenathinlayerofclay.Scientistsfeltthattheycouldgetanideaofhowlongtheextinctionstookbydetermininghowlongittooktodepositthisonecentimeterofclayandtheythoughttheycoulddeterminethetimeittooktodeposittheclaybydeterminingtheamountoft

28、heelementiridium(lr)itcontained.7.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage?Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.ThefossilrecordsuggeststhattherewasanabruptextinctionofmanyplantsandanimalsattheendoftheMes

29、ozoicera.FewfossilsoftheMesozoicerahavesurvivedintherocksthatmarktheendoftheCretaceous.FossilsfromtheCretaceousperiodoftheMesozoicuptothebeginningoftheCenozoicerahavebeenremovedfromthelayersofrockthatsurroundedthem.PlantsandanimalsfromtheMesozoicerawereunabletosurviveintheCenozoicera.Paragraph4:Diss

30、atisfactionwithconventionalexplanationsfordinosaurextinctionsledtoasurprisingobservationthat,inturn,hassuggestedanewhypothesis.ManyplantsandanimalsdisappearabruptlyfromthefossilrecordasonemovesfromlayersofrockdocumentingtheendoftheCretaceousupintorocksrepresentingthebeginningoftheCenozoic(theeraafte

31、rtheMesozoic).BetweenthelastlayerofCretaceousrockandthefirstlayerofCenozoicrock,thereisoftenathinlayerofclay.Scientistsfeltthattheycouldgetanideaofhowlongtheextinctionstookbydetermininghowlongittooktodepositthisonecentimeterofclayandtheythoughttheycoulddeterminethetimeittooktodeposittheclaybydetermi

32、ningtheamountoftheelementiridium(Ir)itcontained.8.Inparagraph4,allthefollowingquestionsareansweredEXCEPT:WhyistherealayerofclaybetweentherocksoftheCretaceousandCenozoic?WhywerescientistsinterestedindetermininghowlongittooktodepositthelayerofclayattheendoftheCretaceous?Whatwastheeffectofthesurprising

33、observationscientistsmade?WhydidscientistswantmoreinformationaboutthedinosaurextinctionsattheendoftheCretaceous?Paragraph5:IrhasnotbeencommonatEarthssincetheverybeginningoftheplanetshistory.Becauseitusuallyexistsinametallicstate,itwaspreferentiallyincorporatedinEarthscoreastheplanetcooledandconsolid

34、ated.Irisfoundinhighconcentrationsinsomemeteorites,inwhichthesolarsystemsoriginalchemicalcompositionispreserved.Eventoday,microscopicmeteoritescontinuallybombardEarth,fallingonbothlandandsea.BymeasuringhowmanyofthesemeteoritesfalltoEarthoveragivenperiodoftime,scientistscanestimatehowlongitmighthavet

35、akentodeposittheobservedamountofIrintheboundaryclay.Thesecalculationssuggestthataperiodofaboutonemillionyearswouldhavebeenrequired.However,otherreliableevidencesuggeststhatthedepositionoftheboundaryclaycouldnothavetakenonemillionyears.SotheunusuallyhighconcentrationofIrseemstorequireaspecialexplanat

36、ion.9.Thewordbombardinthepassageisclosestinmeaningtoapproachstrikepasscircle10.Paragraph5impliesthataspecialexplanationofIrintheboundaryclayisneededbecausetheIrinmicroscopicmeteoritesreachingEarthduringtheCretaceousperiodwouldhavebeenincorporatedintoEarthscoretheIrintheboundaryclaywasdepositedmuchmo

37、rethanamillionyearsagotheconcentrationofIrintheboundaryclayishigherthaninmicroscopicmeteoritestheamountofIrintheboundaryclayistoogreattohavecomefrommicroscopicmeteoritesduringthetimetheboundaryclaywasdepositedParagraph6:Inviewofthesefacts,scientistshypothesizedthatasinglelargeasteroid,about10to15kil

38、ometersacross,collidedwithEarth,andtheresultingfalloutcreatedtheboundaryclay.Theircalculationsshowthattheimpactkickedupadustcloudthatcutoffsunlightforseveralmonths,inhibitingphotosynthesisinplants;decreasedsurfacetemperaturesoncontinentstobelowfreezing;causedextremeepisodesofacidrain;andsignificantl

39、yraisedlong-termglobaltemperaturesthroughthegreenhouseeffect.Thisdisruptionoffoodchainandclimatewouldhaveeradicatedthedinosaursandotherorganismsinlessthanfiftyyears.11.Theworddisruptioninthepassageisclosestinmeaningtoexhaustiondisturbancemodificationdisappearance12.Paragraph6mentionsallofthefollowin

40、geffectsofthehypothesizedasteroidcollisionEXCEPTalargedustcloudthatblockedsunlightanimmediatedropinthesurfacetemperaturesofthecontinentsanextremedecreaseinrainfallonthecontinentsalong-termincreaseinglobaltemperaturesParagraph5:IrhasnotbeencommonatEarthssincetheverybeginningoftheplanetshistory.Becaus

41、eitusuallyexistsinametallicstate,itwaspreferentiallyincorporatedinEarthscoreastheplanetcooledandconsolidated.Irisfoundinhighconcentrationsinsomemeteorites,inwhichthesolarsystemsoriginalchemicalcompositionispreserved.Eventoday,microscopicmeteoritescontinuallybombardEarth,fallingonbothlandandsea.Bymea

42、suringhowmanyofthesemeteoritesfalltoEarthoveragivenperiodoftime,scientistscanestimatehowlongitmighthavetakentodeposittheobservedamountofIrintheboundaryclay.Thesecalculationssuggestthataperiodofaboutonemillionyearswouldhavebeenrequired.However,otherreliableevidencesuggeststhatthedepositionofthebounda

43、ryclaycouldnothavetakenonemillionyears.SotheunusuallyhighconcentrationofIrseemstorequireaspecialexplanation.13.Lookatthefoursquaresthatindicatewherethefollowingsentencecouldbeaddedtothepassage.Consequently,theideathattheIrintheboundaryclaycamefrommicroscopicmeteoritescannotbeaccepted.Wherewouldthese

44、ntencebestfit?14.Directions:Anintroductorysentenceforabriefsummaryofthepassageisprovidedbelow.CompletethesummarybyselectingtheTHREEanswerchoicesthatexpressthemostimportantideasinthepassage.Somesentencesdonotbelonginthesummarybecausetheyexpressthatarenotpresentedinthepassageorareminorideasinthepassag

45、e.Thisquestionisworth2points.Foralongtimescientistshavearguedthattheextinctionofthedinosaurswasrelatedtoclimatechange.AnswerchoicesAsimpleclimatechangedoesnotexplainsomeimportantdatarelatedtotheextinctionofthedinosaursattheendoftheCretaceous.TheretreatoftheseawaysattheendoftheCretaceoushasnotbeenful

46、lyexplained.TheabruptnessofextinctionsattheendoftheCretaceousandthehighconcentrationofIrfoundinclaydepositedatthattimehavefueledthedevelopmentofanewhypothesis.Extremechangesindailyandseasonalclimatesprecededtheretreatoftheseasbackintothemajoroceanbasins.Somescientistshypothesizethattheextinctionofth

47、edinosaursresultedfromtheeffectsofanasteroidcollisionwithEarth.BoundaryclaylayersliketheonebetweentheMesozoicandCenozoicareusedbyscientiststodeterminetherateatwhichanextinctspeciesdeclined托福TPO8浏览答案Part2参考答案：1.42.33.24.15.16.47.18.19.210.411.212.313.314.AsimpleclimatechangeTheabruptnessofextinctions

48、Somescientistshypothesize托福TPO8浏览翻译：Part2参考翻译：恐龙的灭绝很长时间以来，古生物学家们以为恐龙的灭亡是与因地质构造而引起的海洋和大陆位置变迁相关的气候变化所致。在整个白垩纪(中生代的最后的一段时间，这时恐龙正值繁盛)，广阔的浅海覆盖了大量的陆地。各方面的数据，包括海床沉积中的地理化学证据，都表明白垩纪后期的气候比如今的气候要温和得多。白天不是很热，夜间也不是很严寒。夏天不是太炎热，而冬天也不是太严寒。大陆上的浅海可能使其附近的空气少受影响，以保持相对稳定的温度。在白垩纪后期，地质资料表明这些浅海都从大陆退回到主要的海洋盆地内了，没有人明白为什么。大约在100000年内，海洋收缩了，世界的气候也随之变得更极端：白天更热，夜间更冷，夏天更炎热，冬天更严寒。恐龙或许就是由于无法忍耐这种严峻的气温变化因此灭绝。假如真是这样，那么为什么冷血动物，比方蛇类、蜥蜴、乌龟和鳄鱼却能够幸免于寒冬和酷夏呢?这些动物都是依靠于气温以使其身体保持合适生存的温度。很难理解它们为什么毫不受影响，然而恐龙却如此的无能以致于无法适应，尤其是有些科学家以为恐龙是热血动物。批评者们也指出浅海在中生代曾有过无数次的进入大陆而又退回盆地的经过，所以为什么恐龙在前面的海洋起伏中能幸免于难，而在这一次中却不能呢?尽管最初人们这样以为，但是