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Passage44/63The fossilremainsof thefirst flying vertebrates,the pterosaurs,have intriguedpaleontologists formorethan twocenturies.How suchlarge creatures,which weighedin somecases asmuch as a pilotedhang-glider andhad wingspansfrom8to12meters,solved the problems ofpowered flight,and exactlywhatthese creatureswere——reptiles orbirds——are among the questionsscientists havepuzzledover.Perhaps the least controversialassertion about the pterosaursis that they werereptiles.Their skulls,pelvises,and hindfeet arereptilian.The anatomyof theirwings suggeststhat theydid notevolve intotheclass ofbirds.In pterosaursa greatlyelongated fourthfinger ofeach forelimbsupported awing-likemembrane.Theotherfingerswereshortandreptilian,withsharpclaws.Inbirdsthesecondfingeristheprincipalstrutofthewing,which consistsprimarilyoffeathers.Ifthepterosaurswalked onallfours,thethree shortfingers mayhave beenemployed forgrasping.When apterosaur walkedor remainedstationary,the fourthfinger,and withit thewing,could onlyturn upwardin anextended invertedV-shapealongeachsideoftheanimalsbody.The pterosaursresembled bothbirds andbats in their overallstructure andproportions.This isnotsurprising because the designof anyflyingvertebrateis subjectto aerodynamicconstraints.Both thepterosaursand thebirds havehollow bones,a featurethat representsa savingsin weight.In thebirds,however,thesebonesarereinforcedmoremassivelybyinternalstruts.Although scalestypically coverreptiles,the pterosaursprobably hadhairy coats.T.H.Huxley reasonedthatflying vertebratesmust havebeen warm-blooded becauseflying impliesa highrate ofmetabolism,which inturn impliesa highinternal temperature.Huxley speculatedthat acoat ofhair wouldinsulateagainstlossofbodyheatandmightstreamlinethebodytoreduce draginflight.Therecentdiscoveryofa pterosaurspecimen coveredin long,dense,and relativelythick hairlikefossil materialwas thefirstclearevidencethathisreasoningwascorrect.Efforts toexplain howthe pterosaursbecame airbornehave ledto suggestionsthat theylaunchedthemselves byjumping fromcliffs,by droppingfrom trees,or evenby risinginto lightwinds from thecrests ofwaves.Each hypothesishas itsdifficulties.The firstwrongly assumesthat thepterosaurs hindfeetresembledabatsandcouldserveashooksbywhichtheanimalcouldhanginpreparationforflight.The secondhypothesis seemsunlikely becauselarge pterosaurscould nothave landedin treeswithoutdamaging theirwings.The thirdcalls forhigh wavesto channelupdrafts.The windthat madesuchwaveshowever,mighthavebeentoostrongforthepterosaurstocontroltheirflightonceairborne.It canbe inferredfrom the passage thatscientists nowgenerally agreethat theA enormouswingspanofthepterosaursenabledthemtoflygreatdistancesEclarifythedifferencesbetweenanoldexplanationofaphysicalphenomenonandanewmodelofit
22.WhichofthefollowingbestdescribestheorganizationofthefirstparagraphA Atheoryispresentedandcriticized.B Amodelisdescribedandevaluated.C Aresultisreportedanditsimportanceexplained.D Aphenomenonisnotedanditssignificancedebated.E Ahypothesisisintroducedandcontraryevidencepresented.
24.According to the modelpresented in the passage,which of the followingnormally signalsthedisappearanceofanElNinoA ThearrivalintheeasternPacificofnegativesea-levelKelvinwaves.B Ashiftinthedirectionofthewindsproducedbythestartofananti-EINinoelsewhereinthePacific.C Thereflection ofKelvin wavesafter theyreach the eastern boundaryof the Pacific,along EcuadorandPeru.D AnincreaseinthespeedatwhichnegativeRossbywavescrossthePacific.E Thecreation of a reservoirof colder,deep oceanwater trappedunder thepile ofwarmer,surfaceoceanwater.
25.ItcanbeinferredfromthepassagethatwhichofthefollowingwouldresultfairlyimmediatelyfromthecessationofthewindsofanElNinoI NegativeRossbywaveswouldceasetobegeneratedintheeasternPacific.J ThesealevelintheeasternPacificwouldfall.K.ThesurfacewaterintheeasternPacificwouldagainbecooledbybeingmixedwithdeepwater.L IonlyMIIonlyN IandIIonlyOIandIIIonlyP I,II,andIII
26.Whichofthefollowing,iftrue,wouldmostseriouslyunderminethevalidityofthemodelofElNinothatispresentedinthepassageA DuringsomeyearsElNinoextendssignificantlyfartheralongthecoastsofEcuadorandPeruthanduringotheryears.B DuringperiodsofunusuallycooltemperaturesalongtheeasternPacific,anElNinoismuchcolderthannormal.C ThenormalupwellingofcoldwaterintheeasternPacificdependsmuchmoreonthelocalcharacteristicsoftheoceanthanonatmosphericconditions.D ThevariationsinthetimeittakesRossbywavestocrossthePacificdependonthepowerofthewindsthatthewavesencounter.E ThewesternboundaryofthePacificbasinissoirregularthatitimpedesmostcoastalKelvinwavesfromheadingeastward.汉译英1有些人认为多次短时间充电,会对电池造成损害事实上,我们大错特错23英译汉作文therealmeaningofweaponcontrolB structureoftheskeletonofthepterosaurssuggestsacloseevolutionaryrelationshiptobatsCfossilremainsofthepterosaursrevealhowtheysolvedtheproblemofpoweredflightD pterosaurswerereptilesEpterosaurswalkedonallfours
2.TheauthorviewstheideathatthepterosaursbecameairbornebyrisingintolightwindscreatedbywavesasA revolutionaryBunlikelyC unassailableDprobableE outdated
3.Accordingtothepassage,theskeletonofapterosaurcanbedistinguishedfromthatofabirdbytheA sizeofitswingspanBpresenceofhollowspacesinitsbonesC anatomicoriginofitswingstrutDpresenceofhooklikeprojectionsonitshindfeetE locationoftheshoulderjointjoiningthewingtoitsbody
4.TheideasattributedtoT.H.HuxleyinthepassagesuggestthathewouldmostlikelyagreewithwhichofthefollowingstatementsA Ananimal,sbrainsizehaslittlebearingonitsabilitytomastercomplexbehaviors.B Ananimalsappearanceisofteninfluencedbyenvironmentalrequirementsandphysicalcapabilities.C Animalswithinagivenfamilygroupareunlikelytochangetheirappearancedramaticallyoveraperiodoftime.D Theoriginofflightinvertebrateswasanaccidentaldevelopmentratherthantheoutcomeofspecializationoradaptation.E Thepterosaursshouldbeclassifiedasbirds,notreptiles.WhichofthefollowingbestdescribestheorganizationofthelastparagraphofthepassageA Newevidenceisintroducedtosupportatraditionalpointofview.B Threeexplanations fora phenomenon are presented,and eachis disputedby meansof specificinformation.C Threehypothesesareoutlined,andevidencesupportingeachisgiven.D Recentdiscoveriesaredescribed,andtheirimplicationsforfuturestudyareprojected.LSAT第27套SECTIONIMostoffice workersassumethat themessagestheysendtoeach othervia electronicmailare asprivateasa telephonecall ora face-to-face meeting.That assumptionis wrong.Although itis illegalin manyareasforanemployertoeavesdroponprivateconversationsortelephonecalls—eveniftheytake placeona company-owned telephone一there areno clearrules governingelectronic mail.In fact,thequestion ofhow privateelectronic mailtransmissions shouldbe hasemerged asone of the morecomplicatedlegalissuesoftheelectronicage.Peoplesopinionsaboutthedegreeofprivacythatelectronicmailshouldhavevarydependingonwhoseelectronic mailsystem isbeing usedand whois readingthe messages.Does agovernment office,forexample,havetherighttodestroyelectronicmessagescreatedinthecourseofrunningthegovernment,thereby denyingpublic accessto suchdocuments Somehold thatgovernment officesshould issueguidelinesthat allowtheir staffto deletesuch electronicrecords,and defendthis practiceby claimingthat the messagesthus deletedalready existin paperversions whosedestruction isforbidden.Opponents ofsuch practicesargue thatthe paperversions oftenomit suchinformation aswho receivedthemessages andwhen theyreceived them,information commonlycarried onelectronic mailsystems.Government officials,opponents maintain,are civilservants;the publicshould thushave theright toreviewanydocumentscreatedduringtheconductingofgovernmentbusiness.Questions aboutelectronic mailprivacy havealso arisenin theprivate sector.Recently,two employeesofanautomotivecompanywerediscoveredtohavebeencommunicating disparaginginformationabouttheir supervisorvia electronic mail.The supervisor,who hadbeen monitoringthe communication,threatened tofire theemployees.When theemployees fileda grievancecomplaining thattheir privacyhadbeen violated,they werelet go.Later,their courtcase forunlawful terminationwas dismissed;thecompany slawyers successfullyargued thatbecausethecompany ownedthe computer system,itssupervisorshadtherighttoreadanythingcreatedonit.In someareas,laws prohibitoutside interceptionof electronic mail bya thirdparty withoutproperauthorization suchasasearch warrant.However,these lawsdo notcover uinsideinterception suchasoccurredattheautomotivecompany.Inthepast,courtshaveruledthatinterofficecommunicationsmaybeconsideredprivateonlyifemployeeshavea°reasonableexpectationofprivacywhentheysendthemessages.The factis thatno absoluteguarantee of privacy existsin anycomputersystem.The onlysolutionmay befor usersto scrambletheir ownmessages withencryption codes;unfortunately,suchcomplexcodesarelikelytounderminetheprincipalvirtueofelectronicmail:itsconvenience.
1.WhichoneofthefollowingstatementsmostaccuratelysummarizesthemainpointofthepassageA Untilthe legal questions surrounding the privacy of electronic mail in both the public and privatesectors havebeen resolved,office workerswill needto scrambletheir electronicmail messageswithencryptioncodes.B Thelegalquestionssurroundingtheprivacyofelectronicmailintheworkplacecanbestberesolvedbytreating suchcommunications asif theywere asprivate astelephone conversationsor face-to-facemeetings.C Anyattempt toresolve thelegal questionssurrounding theprivacy of electronicmailin theworkplacemust takeinto accountthe essentialdifference betweenpublic-sector andprivate sectorbusiness.D Atpresent,inboththepublicandprivatesectors,there seemto beno cleargeneral answersto thelegalquestionssurroundingtheprivacyofelectronicmailintheworkplace.E Thelegalquestionssurroundingtheprivacyofelectronicmailin theworkplace ofelectronicmailintheworkplacecanbestberesolvedbyallowingsupervisorsinpublic-sectorbutnotprivate-sectorofficestomonitortheiremployeescommunications.
2.According to the passage,which oneof the following bestexpresses thereason somepeople usetoopposethedeletionofelectronicmailrecordsatgovernmentofficesA Suchdeletionrevealstheextentofgovernmentsunhealthyobsessionwithsecrecy.B Suchdeletionrunscountertothenotionofgovernmentsaccountabilitytoitsconstituency.C Suchdeletionclearlyviolatesthelegalrequirementthatgovernmentofficeskeepduplicatecopiesofalltheirtransactions.D Suchdeletionviolatesthegovernment,sownguidelinesagainstdestructionofelectronicrecords.E Suchdeletionharmsrelationsbetweengovernmentemployeesandtheirsupervisors.
3.WhichoneofthefollowingmostaccuratelystatestheorganizationofthepassageA Aproblem isintroduced,followed byspecific examplesillustrating theproblem:a possiblesolutionissuggested,followedbyanacknowledgmentofitsshortcomings.B Aproblemis introduced,followed byexplicationsoftwopossible solutionsto theproblem:thefirstsolutionispreferredtothesecond,andreasonsaregivenforwhyitisthebetteralternative.C Aproblem isintroduced,followed byanalysis of the historicalcircumstances thathelped bringtheproblemaboutapossiblesolutionisofferedandrejectedasbeingonlyapartialremedy.D Aproblem isintroduced,followed byenumeration ofvarious questionsthat needto be answeredbeforeasolutioncanbefound:onepossiblesolutionisproposedandarguedfor.E Aproblem isintroduced,followed bydescriptions oftwo contrastingapproaches tothinking abouttheproblem:thesecondapproachispreferredtothefirst,andreasonsaregivenforwhyitismorelikelytoyieldasuccessfulsolution.
4.Based on thepassage,the authors attitudetowards interceptionofelectronicmail canmostaccuratelybedescribedas:A outrightdisapprovalofthepracticeBsupportforemployerswhoengageinitC supportforemployeeswholosetheirjobsbecauseofitDintellectualinterestinitslegalissuesE cynicismaboutthemotivesbehindthepractice
5.It canbe inferredfrom thepassage thatthe author would most likely holdwhich oneof thefollowingopinions aboutan encryptionsystem thatcould encodesanddecode electronicmail messageswithasinglekeystrokeAIt would beanunreasonable burdenonacompany sability tomonitor electronicmail createdbyitsemployees.B Itwouldsignificantlyreducethedifficultyofattemptingtosafeguardtheprivacyofelectronicmail.C Itwould createsubstantial legalcomplications forcompanies tryingto preventemployees fromrevealingtradesecretstocompetitors.D Itwould guaranteeonly aminimal levelof employeeprivacy,and sowould notbe worththe costinvolvedininstallingsuchasystem.E Itwould requirea changein thelegal definitionof“reasonable expectationofprivacyas itappliestoemployer-employeerelations.SECTIONBSome recenthistorians haveargued thatlife inthe Britishcolonies inAmerica fromapproximately1763to1789was markedby internalconflicts amongcolonists.Inheritors ofsome of the viewpointsof earlytwentieth-century Progressivehistorians suchas Beardand Becker,these recenthistorians haveputforwardargumentsthatdeserveevaluation.Thekindofconflict mostemphasizedbythesehistoriansisclassconflict.YetwiththeRevolutionaryWardominating theseyears,how doesone distinguishclass conflictwithin thatlarger conflictCertainly notbythesideapersonsupported.Althoughmanyofthesehistorianshaveacceptedtheearlierassumptionthat Loyalistsrepresented anupper class,new evidenceindicates thatLoyalists,like rebels,were drawnfromallsocioeconomicclasses.Itisnonethelessprobablytruethatalargerpercentageofthewell-to-dojoined theLoyalists thanjoined the rebels.Looking atthe rebelside,we findlittle evidencefor thecontentionthatlower-classrebelswere inconflictwithupper-classrebels.Indeed,thewar effortagainstBritaintended tosuppress classconflicts.Where itdid not,the disputingrebels ofone oranother classusuallybecame Loyalists.Loyalism thusoperated asa safetyvalve toremove socioeconomicdiscontentthat existedamong the rebels.Disputes occurred,of course,among thosewho remainedonthe rebelside,but theextraordinary socialmobility ofeighteenth-century Americansociety withthe obviousexceptionof slavesusually preventedsuch disputesfrom hardeningalong classlines.Social structurewasin factso fluid-though recentstatistics suggesta narrowingof economicopportunity asthe latterhalfofthecenturyprogressed—thattotalkaboutsocialclassesatallrequirestheuseoflooseeconomiccategoriessuchasrich,poor,andmiddle class,oreighteenth-centurydesignationslike“thebettersort.wDespite thesevague categories,one shouldnot claimunequivocally thathostility betweenrecognizableclassescannotbelegitimatelyobserved.OutsideofNewYork,however,therewereveryfewinstancesofopenlyexpressedclassantagonism.Having saidthis,however;one mustadd thatthere ismuch evidenceto supportthe furtherclaim ofrecenthistorians thatsectional conflictswere commonbetween1763and
1789.The“Paxton Boysincident and the Regulatormovement arerepresentative examplesof thewidespread,and justified,discontent ofwestern settlersagainst colonialor stategovernments dominatedby easterninterests.Although undertonesof classconflict existedbeneath suchhostility,the oppositionwas primarilygeographical.Sectional conflict——which alsoexisted betweenNorth andSouth-deserves furtherinvestigation.In summary,historians mustbe carefulaboutthekind ofconflict theyemphasize ineighteenth-centuryAmerica.Yet thosewho stressthe achievementofageneral consensusamongthecolonists cannotfullyunderstand thatconsensuswithoutunderstanding theconflictsthat hadtobe overcomeorrepressed inordertoreachit.
17.TheauthorconsidersthecontentionsmadebytherecenthistoriansdiscussedinthepassagetobeA potentiallyverifiableBpartiallyjustifiedC logicallycontradictoryDingeniousbutflawedE capriciousandunsupported
19.Accordingtothepassage,LoyalismduringtheAmericanRevolutionaryWarservedthefunctionofA eliminatingthedisputesthatexistedamongthosecolonistswhosupportedtherebelcauseBdrawingupper,asopposedtolower,socioeconomicclassesawayfromtherebelcauseC toleratingthekindsofsocioeconomicdiscontentthatwerenotallowedtoexistontherebelsideDchannelingconflictthatexistedwithinasocioeconomicclassintothewareffortagainsttherebelcauseE absorbingmembersofsocioeconomicgroupsontherebelsidewhofeltthemselvesincontentionwithmembersofothersocioeconomicgroupsThepassage suggeststhatthe authorwouldbe likelyto agreewith which ofthefollowingstatementsaboutthesocialstructureofeighteenth-centuryAmericansocietyI.Itallowedgreatereconomicopportunitythanitdidsocialmobility.II.Itpermittedgreatereconomicopportunitypriorto1750thanafter
1750.III.Itdidnotcontainrigidlydefinedsocioeconomicdivisions.IV.Itpreventedeconomicdisputesfromarisingamongmembersofthesociety.A IandIVonlyBIIandIIIonlyC IIIandIVonlyDI,II,andIIIonlyE I,ll III,andIVz
21.It canbe inferredfrom thepassage thattheauthorwouldbemostlikelyto agreewith whichof thefollowingstatementsregarding socioeconomicclass andsupportfortherebeland LoyalistcausesduringtheAmericanRevolutionaryWarA Identifyinga persons socioeconomicclass istheleastaccurate methodof ascertainingwhich sidethatpersonsupported.B IdentifyingapersonasamemberoftherebeloroftheLoyalistsidedoesnotnecessarilyrevealthatpersonsparticularsocioeconomicclass.C Boththerebeland theLoyalist sidescontained membersof allsocioeconomic classes,althoughtherewerefewerdisputesamongsocioeconomicclassesontheLoyalistside.D Boththerebeland theLoyalist sidescontainedmembersof allsocioeconomic classes,although theLoyalistsidewasmadeupprimarilyofmembersoftheupperclasses.According tothepassage,whichofthefollowingisa truestatement aboutsectional conflictsin Americabetween1763and1789A Theseconflictswereinstigatedbyeasterninterestsagainstwesternsettlers.B TheseconflictswerethemostseriouskindofconflictinAmerica.C Theconflictseventuallyledtoopenlyexpressedclassantagonism.D Theseconflictscontainedanelementofclasshostility.E Theseconflictsweremotivatedbyclassconflicts.The recent,apparently successful,prediction bymathematical modelsof anappearance ofEl Nino-thewarm oceancurrent thatperiodically developsalong thePacific coastof SouthAmerica—has excitedresearchers.Jacob Bjerknespointed outover20years agohow windsmight createeither abnormallywarmor abnormallycold water inthe eastern equatorialPacific.Nonetheless,until thedevelopment ofthemodelsnoonecouldexplainwhyconditionsshouldregularlyshiftfromonetotheother,ashappensintheperiodicoscillationsbetweenappearancesofthewarm ElNinoandthecoldso-calledanti-EINino.The answer,at leastif thecurrent modelthat linksthe behavioroftheocean tothat ofthe atmosphereiscorrect,istobefoundintheocean.It haslong beenknown thatduring an El Nino,two conditionsexist:1unusually warmwater extendsalongthe easternPacific,principally alongthe coastsof Ecuadorand Peru,and2winds blowfrom thewestinto the warmer airrising overthewarmwaterintheeast.These windstend tocreate afeedbackmechanism bydriving thewarmer surfacewater intoapilethat blocksthe normalupwelling ofdeeper;cold waterintheeast andfurther warmstheeasternwater,thus strengtheningthe windstillmore.The contributionofthe model isto showthatthewinds ofanElNino,which raisesea levelin theeast,simultaneously senda signaltothewest loweringsea level.According tothemodel,that signalisgenerated asa negativeRossby wave,a waveof depressed,or negative,sea level,that moveswestwardparalleltothe equator at25to85kilometers perday.Taking monthsto traversethePacific,Rossbywaves marchtothe western boundaryofthePacific basin,which ismodeled asa smoothwall butinrealityconsistsofquiteirregularislandchains,suchasthePhilippinesandIndonesia.When thewaves meetthewesternboundary,they arereflected,andthemodel predictsthat Rossbywaveswill bebroken intonumerous coastalKelvin wavescarrying thesame negativesea-level signal.Theseeventuallyshoot towardtheequator,and thenheadeastwardalongtheequator propelledbytherotationoftheEarthataspeedofabout250kilometersperday.WhenenoughKelvinwavesofsufficientamplitude arrivefromthewestern Pacific,their negativesea-level signalovercomes thefeedbackmechanism tendingto raisethe sealevel,and theybegin todrive thesystem intothe oppositecoldmode.This producesa gradualshift inwinds,one thatwill eventuallysend positivesea-level Rossbywaveswestward,waves thatwill eventuallyreturn ascold cycle-ending positiveKelvin waves,beginninganotherwarmingcycle.
21.TheprimaryfunctionofthepassageasawholeistoA introduceanewexplanationofaphysicalphenomenonBexplainthedifferencebetweentworelatedphysicalphenomenaC illustratethelimitationsofapplyingmathematicstocomplicatedphysicalphenomenaDindicatethedirectionthatresearchintoaparticularphysicalphenomenonshouldtake。