2018考研英语阅读经典试题及答案(2)

新东方在线推荐：2018年考研一次顺利提分课程！！一科不过，全科免费Thefossilremainsofthefirstflyingvertebrates,thepterosaurs,haveintriguedpaleontologistsformorethantwocenturies.Howsuchlargecreatures,whichweighedinsomecasesasmuchasapilotedhang-gliderandhadwingspansfrom8to12meters,solvedtheproblemsofpoweredflight,andexactlywhatthesecreatureswere—reptilesorbirds—areamongthequestionsscientistshavepuzzledover.Perhapstheleastcontroversialassertionaboutthepterosaursisthattheywerereptiles.Theirskulls,pelvises,andhindfeetarereptilian.Theanatomyoftheirwingssuggeststhattheydidnotevolveintotheclassofbirds.Inpterosaursagreatlyelongatedfourthfingerofeachforelimbsupportedawinglikemembrane.Theotherfingerswereshortandreptilian,withsharpclaws.Inbirdsthesecondfingeristheprincipalstrutofthewing,whichconsistsprimarilyoffeathers.Ifthepterosaurswalkedonallfours,thethreeshortfingersmayhavebeenemployedforgrasping.Whenapterosaurwalkedorremainedstationary,thefourthfinger,andwithitthewing,couldonlyturnupwardinanextendedinvertedVshapealongeachsideoftheanimal’sbody.Thepterosaursresembledbothbirdsandbatsintheiroverallstructureandproportions.Thisisnotsurprisingbecausethedesignofanyflyingvertebrateissubjecttoaerodynamicconstraints.Boththepterosaursandthebirdshavehollowbones,afeaturethatrepresentsasavingsinweight.Inthebirds,however,thesebonesarereinforcedmoremassivelybyinternalstruts.Althoughscalestypicallycoverreptiles,thepterosaursprobablyhadhairycoats.T.H.Huxleyreasonedthatflyingvertebratesmusthavebeenwarm-bloodedbecauseflyingimpliesahighrateofmetabolism,whichinturnimpliesahighinternaltemperature.Huxleyspeculatedthatacoatofhairwouldinsulateagainstlossofbodyheatandmightstreamlinethebodytorecedraginflight.Therecentdiscoveryofapterosaurspecimencoveredinlong,dense,andrelativelythickhairlikefossilmaterialwasthefirstclearevidencethathisreasoningwascorrect.Effortstoexplainhowthepterosaursbecameairbornehaveledtosuggestionsthattheylaunchedthemselvesbyjumpingfromcliffs,bydroppingfromtrees,orevenbyrisingintolightwindsfromthecrestsofwaves.Eachhypothesishasitsdifficulties.Thefirstwronglyassumesthatthepterosaurs’hindfeetresembledabat’sandcouldserveashooksbywhichtheanimalcouldhanginpreparationforflight.Thesecondhypothesisseemsunlikelybecauselargepterosaurscouldnothavelandedintreeswithoutdamagingtheirwings.Thethirdcallsforhighwavestochannelupdrafts.Thewindthatmadesuchwaveshowever,mighthavebeentoostrongforthepterosaurstocontroltheirflightonceairborne.1.Itcanbeinferredfromthetextthatscientistnowgenerallyagreethatthe[A]enormouswingspanofthepterosaursenabledthemtoflygreatdistances.[B]structureoftheskeletonofthepterosaurssuggestsacloseevolutionaryrelationshiptobats.[C]fossilremainsofthepterosaursrevealhowtheysolvedtheproblemofpoweredflight.[D]pterosaurswerereptiles.2.Theauthorviewstheideathatthepterosaursbecameairbornebyrisingintolightwindscreatedbywavesas[A]revolutionary.[B]unlikely.[C]unassailable.[D]probable.3.Accordingtothetext,theskeletonofapterosaurcanbedistinguishedfromthatofabirdbythe[A]sizeofitswingspan.[B]presenceofhollowspacesinitsbones.[C]anatomicoriginofitswingstrut.[D]presenceofhooklikeprojectionsonitshindfeet.4.TheideasattributedtoT.H.Huxleyinthetextsuggestthathewouldmostlikelyagreewithwhichofthefollowingstatements?[A]Ananimal’sbrainsizehaslittlebearingonitsabilitytomastercomplexbehaviors.[B]Ananimal’sappearanceisofteninfluencedbyenvironmentalrequirementsandphysicalcapabilities.[C]Animalswithinagivenfamilygroupareunlikelytochangetheirappearancedramaticallyoveraperiodoftime.[D]Theoriginofflightinvertebrateswasanaccidentaldevelopmentratherthantheoutcomeofspecializationoradaptation.5.Whichofthefollowingbestdescribestheorganizationofthelastparagraphofthetext?[A]Newevidenceisintrocedtosupportatraditionalpointofview.[B]Threeexplanationsforaphenomenonarepresentedandeachisdisputedbymeansofspecificinformation.[C]Threehypothesesareoutlinedandevidencesupportingeachisgiven.[D]Recentdiscoveriesaredescribedandtheirimplicationsforfuturestudyareprojected.