LSAT_CR(9702)_真題詳解(官方解釋)

1、Section1Time35minutes25QuestionsSeaturtlehatchlingsleavingtheirhatchinggroundsonFloridabeachesreachoceancurrentsbyswimmingtothenortheast,asdefinedbythenorthoftheEarthsmagneticfield.Floridahatchlingsplacedinalargeindoortankalsoswimtowardthenortheast.Butwhenthetankissurroundedbyanartificialmagneticfie

2、ldtwiceasstrongastheEarthsfieldandoppositeindirection,thehatchlingsswiminthedirectionoppositetothatinwhichtheyswimwithouttheartificialmagneticfield.Theinformationinthestatementsabovemoststronglysupportswhichoneofthefollowing?Oncebabyseaturtlesreachtheopensea,theyjoingroupsofadultsintheNorthAtlantic.

3、ThedirectioninwhichoceancurrentsflowisdeterminedbythemagneticfieldoftheEarth.BabyseaturtlesareabletosensethemagneticfieldoftheEarth.Noseaturtleeverreturnstothebeachwhereithatched.IfaseaturtlehatchesonthecoastofAfrica,itwillswimtowardthesouthwest.GeneralDescription:Thisquestionasksyoutodrawaninferenc

4、ebasedontheinformationpresented.Itisnotenoughthataresponsebetrue,iftheinformationinthatresponseisirrelevanttotheinformationpresented.Norisitsufficientthataresponsepresentinformationthatismerelyconsistentwiththeinformationpresentedinthepassage;thebestanswermustpresentinformationthatissupportedbythein

5、formationinthepassage.Incorrect.Sincethepassagedoesnotsayanythingaboutadultseaturtles,oraboutthelocationoftheadults,thisclaimisnotsupportedbyinformationinthepassage.Incorrect.ThepassagedoesnotprovideanyinformationabouttherelationbetweenoceancurrentsandthemagneticfieldoftheEarth,andsothisresponseisno

6、tcorrect.Correct.Thoughthepassagedoesnotdrawtheconclusionthatbabyseaturtlescansensethemagneticfield,thefactthatthehatchlingchangetheirdirectioncertainlysuggeststhatthehatchlingsarerespondingtochangesinthemagneticfield.Andifthehatchlingsrespondtothechanges,thenonreasonableinferenceisthattheyareableto

7、sensethemagneticfield.So,thisisthebestanswer.Incorrect.Theinformationinthepassageaboutthebehaviorofseaturtlehatchlingsinthewilddealsonlywiththeirbehaviorastheyleavetheirhatchinggrounds.Itprovidesnosupportforaclaimabouttheseaturtlesbehavioraftertheyhavelefttheirhatchingrounds.Incorrect.Thepassagedoes

8、notprovideanyinformationthatwouldjustifyaninferenceaboutthebehaviorofhatchlingsonthecoastofAfrica.DifficultyLevel:EasyTipsandPitfalls:Readquestionscarefully.Ifaquestionaskswhichstatementissupportedbythepassage,donotchoosearesponsejustbecauseitseemsonindependentgroundstobeplausibleorlikely-youmustpic

9、karesponsebasedontheinformationgiveninthepassage.Question2-3TwentypercentofthepopulationofSpringhillhasbeentoItalyatleastonceinthelastfiveyears,andthirtypercentofthepopulationofSpringhillhasbeentoFranceatleastonceinthelastfiveyears.Therefore,halfofthepopulationofSpringhillhasbeentoEuropeatleastoncei

10、nthelastfiveyears.TheargumentisfaultybecauseitignoresthepossibilitythatsomeofthepopulationofSpringhillhasbeenneithertoItalynortoFranceinthelastfiveyears.someofthepopulationofSpringhillhasbeenbothtoItalyandtoFranceinthelastfiveyears.someofthepopulationofSpringhillhasbeeneithertoItalyortoFranceinthela

11、stfiveyears,butnottoboth.noneofthepopulationofSpringhillhasbeentoanycountryinEuropeotherthanItalyorFranceinthelastfiveyears.noneofthepopulationofSpringhillhasbeeneithertoItalyortoFrancemorethanonceinthelastfiveyears.GeneralDescription:Thisquestionasksyoutoidentifythelogicalprobleminanargumentcausedb

12、yfailuretoconsideralogicallyrelevantpossibility.Thebestanswer,then,willnotmerelypresentsomepossibilitytheargumentfailstoconsider.Rather,itwillbesomethingtheargumentshouldhaveconsidered:apossibilitythat,ifitturnedouttobetrue,wouldtendtounderminethereasoningleadingtotheargumentsconclusion.Incorrect.It

13、wouldnotmaketheargumentflawedtohaveignoredthispossibility:theargumentsconclusionisconsistentwiththepossibilitythattheotherhalfofSpringhillspopulationhasneverbeentoEuropeatall.Becausetheconclusionisconsistentwiththispossibility,theargumentdoesnotneedtoaddressit.Correct.Iftherewerenooverlapbetweenthet

14、ravelerstoItalyandtheTravelerstoFrance,thentheargumentspremiseswouldprovidegoodevidenceforitsconclusion:20%+30%=50%.Buttheargumenthaspresentednoreasontosupposethatthereisnosuchoverlap,andtotheextentthatthereis,theargumentisundermined.Thatis,ifsomepeoplearecountedbothintheItalygroupandintheFrancegrou

15、p,thenthetwogroupstogetherdonotaddupto50%.(B)describesjustthisproblemandisthebestanswer.Incorrect.Farfromignoringthispossibility,theargumentseemstobeassumingthatitisactual.Infact,thegreaterthenumberofpeoplefromSpringhillwhohavebeentoItalyortoFranceinthelastfiveyears,butnottoboth,thestrongertheargume

16、nt.Farfromignoringthispossibility,theargumentseemstobeassumingthatitisactual.ForiftherewerepeopleFORMSpringhillwhohadbeentootherEuropeancountriesinthelastfiveyears,theargumentwouldbestrongerformentioningthem.Incorrect.Theargumentisnotfaultyinignoringthispossibility,becauseitisirrelevant:Theargumenti

17、saboutnumbersofpeoplewhohavebeentoItalyand/orFrance(andthusEurope)atleastonceinthelastfiveyears.DifficultyLevel:EasyTipsandPitfalls:ThoughansweringLSATquestionsdoesnotrequireperFORMinganymathematicalcalculations,thequestionsdoassumeacollege-levelunderstandingofconceptsthatmaybetermed“mathematical,”i

18、ncluding“percent.”McBridesandLeggettsstatementscommitthemtodisagreeingaboutthetruthofwhichoneofthefollowing?Themanufactureoffull-sizecarsshouldbediscouraged.Fuelconservationislessimportantthansafetyincaseofacollision.Whenafull-sizecarandasubcompactcarcollide,theoccupantsofthefull-sizecararelesslikel

19、ythantheoccupantsofthesubcompactcartobeseriouslyinjured.Reducingthenumberoffull-sizecarsonthehighwaywillreducethefrequencyofcollisionsbetweenautomobiles.Thenewfuel-efficiencystandardswillencourageautomobilemanufacturerstobuildmoresubcompactcars.GeneralDescription:Sincethequestionasksyoutodetermineap

20、ointofdisagreementbetweenMcBrideandLeggett,thebestanswerwillbetheondescribingapointthatMcBrideacceptsandLeggettrejectsorviceversa.Correct.McBrideopposestheintroductionoffuel-efficiencystandardspreciselybecausethesestandardswilldiscouragethemanufactureoffull-sizecars,callingthatprospect“troubling.”So

21、McBridewoulddisagreewith(A).Leggett,ontheotherhande,xplicitlydisagreeswithMcBridesposition,arguingthatthestandardsoughttobesupportedpreciselybecausetheydiscouragethemanufactureoffull-sizecarsandthusagreeingwith(A).Thus,(A)isthebestanswer.Incorrect.ThoughMcBrideandLeggettdisagreeaboutwhetherthestanda

22、rdsshouldbeimplemented,bothclearlyareinterestedintheissueofsafety,anditisquiteplausiblethatoneorbothbelievethatfuelconservationislessimportantthanissafety.However,thiscanbethebestansweronlyifthereisevidencethateitherLeggettorMcBridebelievesthatfuelconservationisnotlessimportantthanissafety;thepassag

23、e,however,providesnogroundsforsuchaninference.Incorrect.ThepassagedoesnotprovideenoughinformationtojudgewhetherMcBrideandLeggettdisagreeonthispoint.McBridescommentssuggestagreementwithit,butitisnotclearwhereLeggettstandsontheclaiminquestion.Leggettsaysonlythatitismorelikelythatsomeonewillbeseriously

24、injuredinacollisionifoneofthecarsisfull-size,withoutspecifyingthelocationoftheinjuredperson.Incorrect.NeitherLeggettnorMcBridementionsanythingaboutthefrequencyofaccidents;botharemoreconcernedwiththelikelihoodofharmshouldbeaccidentoccur.Incorrect.BothLeggettandMcBrideagreethatthenewfuel-efficiencysta

25、ndardswilldiscourageautomobilemanufacturersfrombuildingfull-sizecars.However,itisnotclearthateitherbelievesthatthestandardswillencouragethemanufactureofmoresubcompactcars(asopposedtosomethirdkindofcar).Further,evenifitistruethatthereductioninfull-sizecarscausesanincreaseinthemanufactureofsubcompactc

26、ars,thisisapointofagreement,notdisagreement,betweenLeggettandMcBride.Ofthosewhoansweredthisquestionincorrectly,themajoritychose(E),perhapsconfusingtheissueofwhethermanufacturersshouldbeencouragedtobuildmoresubcompactcarswiththeissueofwhethertheywillbeencouragedtodoso.DifficultyLevel:DifficultTipsand

27、Pitfalls:Whenaskedtodetermineapointonwhichtwospeakersarecommittedtoagreementordisagreement,besuretonarrowyourfocustoexplicitassertionsbythespeaker;avoidthetemptationtospeculateaboutwhat(elst)eitherspeakermightbelieve.WhichoneofthefollowingargumentativestrategiesdoesLeggettuseinattemptingtorefuteMcBr

28、idesposition?demonstratingthatMcBridesclaimsarecontradictorychallengingtheunstatedassumptionthatallcarsareeitherfull-sizeorsubcompactshiftingtheperspectivefromwhichtheissueofautomobilesafetyisconsideredraisingdoubtsabouttheaccuracyofageneralizationmadebyMcBridedemonstratingthatitisimpossibletofollow

29、thecourseofactionadvocatedbyMcBrideGeneralDescription:ThisquestionasksyoutofindthedescriptionofstrategyusedbyLeggettinarguingagainstMcBride.Incorrect.McBridesandLeggettsconclusionscontradictoneanother,butthereisnosuggestionthatMcBridesstatementsthemselvescontradictoneanother.Incorrect.Thoughthediscu

30、ssionfocusesonlyonfull-sizeandsubcompactcars,neitherpartyispresumingthatallcarsareeitherfull-sizeorsubcompact.Correct.FromMcBridesperspective,discouragingthemanufactureoffull-sizecarsisabadthing,becauseMcBrideisconsideringtherelativesafetyofacollisionoftwofull-sizecarsanda“mixed”collisioninvolvingon

31、efull-sizeandonesubcompactcar.Leggettisshiftingtheperspective:Insteadofcomparingamixedcollisiontoacollisionoftwofull-sizecars,Leggettcomparesatwo-carcollisioninvolvingafull-sizecartoacollisionoftwosubcompactcars.Fromthatperspective,discouragingthemanufactureoffull-sizecarsisagoodthing,becauseacollis

32、ionoftwosubcompactcarsissagerthanacollisioninvolvingafull-sizecar.Thetwoagreethatthenewfuel-efficiencystandardswilldiscouragethemanufactureoffull-sizecars,buttakedifferentperspectivesontheimplicationofthatforautomobilesafetyandsoreachoppositeconclusionsaboutwhetherthenewstandardsshouldbesupported.In

33、correct.LeggettisraisingdoubtsonlyabouttheconclusionMcBridedrawsfromtheevidence,andthatconclusionis“Thenewfuel-efficiencystandardsshouldthereforebeopposed,”whichisnotageneralization.Thiswasthemostpopularincorrectanswer.The“courseofactionadvocatedbyMcBride”istoopposethenewfuel-efficiencystandards.Leg

34、gettissimplyarguinginfavorofsupportingthem,notclaimingthatisimpossibletakeMcBridescourse.DifficultyLevel:DifficultTipsandPitfalls:Inansweringquestionsabout“argumentativestrategy,”itisimperativethatyouunderstandthestructureoftheargumentinquestion.Youalsoneedtobeabletocomparethestrategiesdescribedinth

35、eresponsestotheargumentstructureinthepassage:Iftheresponsesstrategycannotbemappedexactlyontotheargumentstructure,thatresponseisnotthebestanswer.Concernsfortheenvironmenthaveledchemiststodevelopplasticsthataredegradable.Alldegradableplastics,whicharepotentiallyusefulpackagingmaterials,needjusttherigh

36、tconditionstobreakdown.Someneedexposuretosunlight,someneedtobeburiedinsoilandsomeneedtobesubmergedinwater.Itshouldbecautionedthatsomedegradableplasticsleaveresiduesofunknowntoxicity.Ifallofthestatementsabovearetrue,whichoneofthefollowingmustalsobetrue?Somematerialsthatarepotentiallyusefulforpackagin

37、gleaveresiduesofunknowntoxicity.Somedegradableplasticsneedbothsunlightandsubmersioninordertobreakdown.Somematerialsthatneedsunlightinordertobreakdownarenotpotentiallyusefulpackagingmaterials.Somematerialsthatleaveresiduesofunknowntoxicityarenotdegradableplastics.Somematerialsthatneedtobeburiedinsoil

38、tobreakdownleaveresiduesofunknowntoxicity.GeneralDescription:Thisquestionasksyoutodeterminewhichoneoftheresponsesmustbetrue,giventheinfointhepassage.Thisisaverystrongrequirement.Itmaybeeasiertothinkofthetaskatdeterminingwhichchoicecannotbefalse,ifthestatementsinthepassagearetrue.Thenyoucanruleoutany

39、choicethatcouldbefalse.Correct.Sincethepassagetellsusthatalldegradableplasticsarepotentiallyusefulpackagingmaterials,andalsothatsomedegradableplasticsleaveresiduesofunknowntoxicity,itisnecessarilytruethatsomepotentiallyusefulpackagingmaterials(namely,thosedegradableplastics)leaveresiduesofunknowntox

40、icity.Thisisthebestanswer.Incorrect.Thoughtitispossiblethatsomeplasticswouldneedbothsunlightandsubmersioninordertodecompose,thepassagemerelystatesthatatleastoneisnecessary.So,contraryto(B)itisquitepossiblethatonlysunlightorsubmersionisneeded,andthusitisquitepossiblethat(B)isfalse.Incorrect.Thepassag

41、efocusessolelyonthestatusofdegradableplastics.However,itisquitepossiblethattherearesomeothermaterials-thatis,nonplasticmaterials-thatneedsunlighttobreakdown.Iftherearenosuchmaterials,ofcourse,theresponseneednotbetrue.Butevenifthereare,thepassagegivesnoinfoaboutthestatusofthesematerials-theymightormi

42、ghtnotbepotentiallyusefulpackagingmaterials.Soinanycase,(C)neednotbetrue.Incorrect.Thepassagesaysthatsomedegradableplasticsleaveresiduesofunknowntoxicity,butitdoesnotsaywhetheranysubstancesotherthandegradableplasticsleavesuchresidues.Forallweknowfromthepassage,thosedegradableplasticsaretheonlymateri

43、alsthatleavesuchresidues.Consequently,itisquitepossiblethatallmaterialsthatleaveresiduesofunknowntoxicityaredegradableplastics,andthusitispossibleforthisstatementtobefalse.Incorrect.Thischoicecertainlyisperfectlyconsistentwiththeinfointhepassage,andthusitcertainlymaybetrue.Butitmaybeinsteadthatthese

44、residuesareleftnotbyplasticsthatneedtobeburiedinsoiltobreakdown,butratheronlybytheplasticsthatrequiresubmersioninwaterorexposuretosunlighttobreakdown.Thus,itispossibleforthisstatementtobefalse.DifficultyLevel:RelativelyeasyTipsandPitfalls:Keepinmindthatwhatmustbetruecannotbefalseandviceversa;indiffe

45、rentquestionsandwithdifferentresponses,conceivingofthequestioninoneofthesewaysortheothermaybeeasierforyou.Itisalsoworthrepeatingthatmustbetrue(aswellascannotbefalse)isaverystrongrequirement:nothingthatmerelymightbetrue,couldbetrue,orevenisquitelikelytobetruewillbethebestanswer.Questions6-7Thecominge

46、conomicrecoverywillsurelybestrong.Mostoftheeconomistsininvestmentcompaniesnowagreethatthisisso,thoughttheleadingacademiceconomistsstillthinkotherwise.Sincetheinvestmentcompanieseconomistsareriskingtheirjobswhentheymakeforecasts,whereasacademiceconomistshavelifelongtenure,itgenerallymakessensetotaket

47、heinvestmentcompanieseconomistsmoreseriously.Themainconclusionoftheargumentissupportedonlybycomparingthenumberofexpertswhoagreewiththeconclusionwiththenumberwhodisagreewiththeconclusionthroughanassessmentofthelikelyrisksandconsequencesofbelievingoneoranotherstrandofexpertopinionthroughprojectionfrom

48、theeconomicprospectsforinvestmentcompaniestoeconomicprospectsfortheeconomyasawholethroughanassessmentoftherelativereliabilityoftheexpertswhoagreewiththeconclusionascomparedwiththatofthosewhodisagreebyattackingthecharacterofthoseexpertswhodisagreewiththeconclusionGeneralDescription:Toanswerthisquesti

49、on,youmustfirstrecognizeexactlywhatisthemainconclusionoftheargument.Thenyoushouldbeabletoconsiderhowtheargumentgoesaboutsupportingthatconclusion.Youalsoneedtobeabletocomparethemethodsofsupportdescribedintheresponsestotheargumentinthepassage:iftheresponsesmethoddoesnotcorrespondexactlytothatusedinthe

50、argument,thatresponseisnotthebestanswer.Incorrect.Thenumberofexpertsoneachsidedoesnotarise;rather,qualitiesoftheexpertsoneachsidearediscussed.Incorrect.Theideaofrisksandconsequencesdoesariseintheargument,whichmayaccountforthepopularityofthisincorrectanswer(chosenbythevastmajorityofthosetesttakerswho

51、answeredthisquestionincorrectly).Buttherisksandconsequencesdiscussedarerisksandconsequencesfortheexpertsthemselves,notforthepeoplewhomayormaynotbelievethoseexperts.Incorrect.Theeconomicprospectsforinvestmentcompaniesarenotmentionedatall.Further,thougheconomicprospectsforemployeesofsuchcompaniesarise

52、indirectly,eventheseprospectsarenot“projected”ontotheeconomyasawhole.Correct.Theargumentpointsoutthattheeconomistswhosupportitsconclusionarethosewhorisktheirjobsinmakingforecasts.Ifonegroupofexpertsisriskingtheirjobsinmakingcertainforecasts,thatgrouphasaprimafaciereasontobemorecarefulinmakingsuchfor

53、ecaststhandoesagroupofexpertsnotriskingtheirjobsinmakingsuchforecasts.This,theargumentsuggests,isareasontothinkthatthefirstgroupofexpertsismorereliablethanthesecond,andthusareasontobelievetheforecastmadebythefirstgroup,namely,thatthecomingeconomicrecoverywillbestrong.So(D)isthebestanswer.Incorrect.I

54、tistoostrongtocallthisargumentan“attack”onanyones“character”:theargumentsimplypointsoutfactsaboutthetwogroupsofexperts.DifficultyLevel:DifficultTips&Pitfalls:Keepinmindthatforaresponsetobethebestanswer,itisnotsufficientthatitbeconnectedtopassageinsomewayorother;itmustrelateinthespecificwaystatedinth

55、equestion.Whichoneofthefollowing,iftrueaboutthepredictionsofinvestmentcompanieseconomists,mostseriouslyweakenstheargument?Theircontentislikelytobedictatedasmuchbytheinterestsoftheeconomistsemployerasbyanobjectiveassessmentoftheeconomy.Theyarelikelytohavemoreeffectontheeconomicclimatethanarethepredic

56、tionsofacademiceconomists.Themethodsusedinarrivingatthemincludefactorsnotemployedbyacademiceconomists.Theiraccuracyisanimportantfactoraffectingtheprofitabilityoftheinvestmentcompanies.Theyaremorereliablewhentheydisagreewiththanwhentheyagreewiththepredictionsofacademiceconomists.GeneralDescription:Th

57、epassageissuggestingthattheinformationprovidedbytheinvestmentcompanieseconomistsismoretrustworthythantheinformationprovidedbyacademiceconomists.So,aclaimthatweakenstheargumentwouldbeonethatweakensthetrustworthinessoftheinformationfromtheinvestmentcompanyseconomists(oraclaimthatincreasesthetrustworth

58、inessoftheacademiceconomists).Correct.Iftheinterestsoftheeconomistsemployerarelikelytoaffecttheeconomistspredictionsasmuchasdomoreobjectivefactors,thisprovidesareasontodoubtthepredictions.Thepredictionsstillmightbeaccurate,dependingonwhatexactlytheinterestsoftheemployerare,butonthefaceofit,response(

59、A)struthtendstoweakentheargumentinfavoroftakingtheinvestmentcompanieseconomistsmoreseriouslythantheacademiceconomists.Thus(A)isthebestanswer.Incorrect.Atbest,thischoiceisirrelevanttotheconclusionoftheargument;atworst,thischoicesupportstheconclusionbygivingareasonthatforecastsofinvestmentcompanyecono

60、mistsshouldbetakenmoreseriously.Thisistemptingchoice,becauseonemightreasonthatiftheinvestmentcompanyeconomistsincludefactorsthatmaketheirmethodsproblematic,andtheacademicsdont,thentheiruseofthesemethodswouldleadonetodoubttheaccuracyofthepredictionsmadebytheinvestmentcompanyeconomists.However,itisequ