2023年研究生類研究生管理科學(xué)入學(xué)考試(GMAT)參考歷年高頻考題帶答案難題附詳解

2023年研究生類研究生管理科學(xué)入學(xué)考試(GMAT)參考歷年高頻考題帶答案難題附詳解（圖片大小可自由調(diào)整）第1卷一.歷年考點試題黑鉆版(共25題)1.Biologistswithapredilectionfortheoryhavetried—andlargelyfailed—todefinewhatitisthatmakessomethingalivingthing.Organismstakeinenergy-providingmaterialsandexcretewasteproducts,butsodoautomobiles.Livingthingsreplicateandtakepartinevolution,butsodosomecomputerprograms.Wemustbeopentothepossibilitythattherearelivingthingsonotherplanets.Therefore,wewillnotbesuccessfulindefiningwhatitisthatmakessomethingalivingthingmerelybyexamininglivingthingsonEarth—theonlyonesweknow.Tryingtodosoisanalogoustotryingtospecify______.

Whichofthefollowingmostlogicallycompletesthepassage?A.thelawsofphysicsbyusingpuremathematicsB.whatafishisbylistingitschemicalcomponentsC.whatananimalisbyexaminingaplantD.whatamachineisbyexaminingasketchofitE.whatamammalisbyexaminingazebra2.Theaverage(arithmeticmean)ofthepositiveintegersx,y,andzis3.Ifx＜y＜z,whatisthegreatestpossiblevalueofz?A.5B.6C.7D.8E.93.Ifyisanoddinteger,whichofthefollowingmustbeaneveninteger?A.y+2B.y+6C.2y-1D.3yE.3y+14.Ofthefollowing,whichisleast?

A.

B.

C.

D.

E.5.Thedeclineinthepriceofbiotechstockshashurtmanyinstitutionsthathadinvestedheavilyinbiotechcompanies.Lastyearthestateuniversityadded200,000sharesofabiotechstocktoitsholdings.Thestockinquestionhasdeclinedinvaluebymorethan90percentoverthelast12months.Thecollege,however,didnotpurchasethestock,butreceiveditasagift.Therefore,thepricedeclinewillnotharmtheuniversity'sfinances.

Whichofthefollowing,iftrue,caststhemostdoubtontheconclusionthatthepricedeclineofbiotechstockswillnotharmtheuniversity'sfinances?A.Thebiotechsectorisvolatile;somestocksthatlose90percentoftheirvalueinoneyearmayregainalloftheirvalueandmoreinthefollowingyear.B.Theuniversityneedstopaycapitalgainstaxesonlyonastocksalethatresultsinagain;stockssoldatalosswillincurnotaxpenalty.C.Althoughthebiotechsectorisdown,theoverallhealth-caresector,inwhichtheuniversityhasinvestedheavily,isupfortheyear.D.ThebiotechcompanyinquestionhasapromisingnewdrugindevelopmentthatcouldrevolutionizethetreatmentoftypeⅡdiabetes.E.Theuniversitybeganconstructionofanewlaboratorylastyearthattheprovosthadexpectedtopayforwiththeproceedsfromthesaleofthebiotechstockinquestion.6.Smokinginbedhaslongbeenthemaincauseofhomefires.Despiteasignificantdeclineincigarettesmokinginthelasttwodecades,however,therehasbeennocomparabledeclineinthenumberofpeoplekilledinhomefires.Eachoneofthefollowingstatements,iftrueoverthelasttwodecades,helpstoresolvetheapparentdiscrepancyaboveEXCEPT:A.Comparedtoothertypesofhomefires,

homefirescausedbysmokinginbedusuallycauserelativelylittledamagebeforetheyareextinguished.B.Homefirescausedbysmokinginbedoftenbreakoutafterthehome'soccupantshavefallenasleep.C.Smokerswhosmokeinbedtendtobeheavysmokerswhoarelesslikelytoquitsmokersthanaresmokerswhodonotsmokinginbed.D.Anincreasingnumberofpeoplehavebeenkilledinhomefiresthatstartedinthekitchen.E.Populationdensitieshaveincreased,withtheresultthatonehomefirecancausemoredeathsthaninpreviousdecades.7.Asurveyofemployersfoundthatduring1993employmentcostsrose3.5percent,whereemploymentcostsconsistofsalarycostsandfringe-benefitcosts.Ifsalarycostsrose3percentandfringe-benefitcostsrose5.5percentduring1993,thenfringe-benefitcostsrepresentedwhatpercentofemploymentcostsatthebeginningof1993?A.16.5%B.20%C.35%D.55%E.65%8.Whatisthegreatestpossiblelengthofapositiveintegerlessthan1,000?A.10B.9C.8D.7E.69.Whichofthefollowingbestcompletesthepassagebelow?"Government"doesnotexistasanindependententitydefiningpolicy.

Insteadthereexistsagroupofdemocraticallyelectedpragmatistssensitivetotheelectorate,whoestablishpoliciesthatwillresultintheirownreelection.Therefore,ifpublicpolicyishostileto,say,environmentalconcerns,itisnotbecauseofgovernmentalperversitybutbecauseelectedofficialsbelievethatA.environmentalistswouldbeextremelydifficulttosatisfywithanypolicy,howeverenvironmentallyround.B.environmentalconcernsarebeingaccommodatedaswellaspublicfundspermit.C.thepublicisoverlyanxiousaboutenvironmentaldeterioration.D.themajorityofvotersvoteforcertainpoliticiansbecauseofthosepoliticians'idiosyncraticpositionsonpolicyissues.E.themajorityofvotersdonotstronglywishforadifferentpolicy.10.Oneofthebiggestthreatstoacompany'sproductivityisabsenteeism.Studieshaveshownthatcompanieswithin-housechildcareprogramsseefewerabsencesamongtheiremployeeswhoareparentsthancompanieswithoutsuchprograms.Therefore,manycompaniescouldboosttheirproductivitybystartingin-housechildcareprograms.

Whichofthefollowing,iftrue,mostweakenstheaboveargument?A.Companiesthatreimburseoutsidechildcareprogramsactuallyseelessabsenteeismamongworkingparentsthancompanieswithin-houseprograms.B.In-housechildcareprogramscreatedistractionsfornonparentsthatcanharmtheirproductivity.C.Absenteeismisnotaseriousproblemforcompaniesthatimposeharshpenaltiesonemployeeswhomisswork.D.Studieshaveshownthatemployeeswithchildrenaremorelikelythanthosewithoutchildrentoremaininthesamejobformorethanfiveyears.E.Potentialemployeesgenerallyviewcompanieswithin-housechildcareprogramsasmoredesirableplacestoworkthancompanieswithoutsuchprograms.11.Agroupofpaintingsmadeapproximately15,000yearsagoinacaveintheLoireRivervalleyinwhatisnowFrancedepictsanumberofdifferentanimals.Oneoftheanimalsdepictedseemstoresemblethechiru,arareantelopeoftheHimalayas.

Whichofthefollowing,iftrue,bestsupportsthehypothesisthatinpaintingtheanimalthatresemblesachiruthecaveartistpaintedachiruwithwhichsheorhewasfamiliar?A.Therearenumerousrepresentationsofimaginaryanimalsincavepaintingsofsimilarage.B.Fossilizedremainsofachiru,approximately16,000yearsold,havebeenfoundatthenorthernendofthevalley.C.Thecavethatcontainsthedepictionofananimalthatresemblesachirucontainsstylizedrepresentationsofplantlife.D.Oldercavesfromthesameregioncontainnorepresentationsofanimalsthatresembleachiru.E.TheantlersoftheanimalinthepaintingarelongerthanthoseofthematureHimalayanchiru.12.InColoradosubalpinemeadows,nonnativedandelionsco-occurwithanativeflower,thelarkspur.Bumblebeesvisitbothspecies,creatingthepotentialforinteractionsbetweenthetwospecieswithrespecttopollination.Inarecentstudy,researchersselected16plotscontainingbothspecies;alldandelionswereremovedfromeightplots;theremainingeightcontrolplotswereleftundisturbed.Thecontrolplotsyieldedsignificantlymorelarkspurseedsthanthedandelion-freeplots,leadingtheresearcherstoconcludethatthepresenceofdandelionsfacilitatespollination(andhenceseedproduction)inthenativespeciesbyattractingmorepollinatorstothemixedplots.

Whichofthefollowing,iftrue,mostseriouslyunderminestheresearchers'reasoning?A.Bumblebeespreferentiallyvisitdandelionsoverlarkspursinmixedplots.B.Inmixedplots,pollinatorscantransferpollenfromonespeciestoanothertoaugmentseedproduction.C.Ifleftunchecked,nonnativespecieslikedandelionsquicklycrowdoutnativespecies.D.Seedgerminationisamorereliablemeasureofaspecies'fitnessthanseedproduction.E.Soildisturbancescanresultinfewerblooms,andhencelowerseedproduction.13.Colorlessdiamondscancommandhighpricesasgemstones.Atypeoflessvaluablediamondscanbetreatedtoremoveallcolor.Onlysophisticatedtestscandistinguishsuchtreateddiamondsfromnaturallycolorlessones.However,only2percentofdiamondsminedareofthecoloredtypethatcanbesuccessfullytreated,andmanyofthoseareofinsufficientqualitytomakethetreatmentworthwhile.Surely,therefore,thevastmajorityofcolorlessdiamondssoldbyjewelersarenaturallycolorless.

AseriousflawinthereasoningoftheargumentisthatA.comparisonsbetweenthepricediamondscommandasgemstonesandtheirvalueforotherusesareomittedB.informationabouttherarityoftreateddiamondsisnotcombinedwithinformationabouttherarityofnaturallycolorless,gemstonediamondsC.thepossibilitythatcoloreddiamondsmightbeusedasgemstones,evenwithouthavingbeentreated,isignoredD.thecurrentlyavailablemethodformakingcolorlessdiamondsfromcoloredonesistreatedasthoughitweretheonlypossiblemethodfordoingsoE.thedifficultythatacustomerofajewelerwouldhaveindistinguishinganaturallycolorlessdiamondfromatreatedoneisnottakenintoaccount14.Whatisthemaximumnumberofcubeswithsidesofalengththatcouldfit

insideacubewithsidesoflength2s?A.8B.16C.32D.64E.12815.Whenairlineswerederegulatedinthe1970s,theaveragepriceofaticketwas$135.Threedecadeslater,theaveragepriceis$275,therearetwiceasmanyin-aircollisions,fliersinsmallmarketsareatthemercyofpredatorycarriers,andairrageisatanall-timehigh.Itistimetore-regulatetheairtravelindustry.

Allofthefollowingstatements,iftrue,weakentheaboveargumentexceptforwhichstatement?A.Becauseofinflation,a$275tickettodayisactually10to20percentlessexpensivethana$135ticketwasin1975.B.Deregulationhasincreasedthechoicesavailabletofliersintermsofbothtimeofflightandcarrier.C.Airlinesarecurrentlyflyingmorethanfivetimesasmanypassengermilesperyearastheydidin1975.D.Comparedwithpassengersinlargeurbanareas,passengersinsmallmarketspay,onaverage,twiceasmuchpermileflownondomesticflightsbecausetheirairportsaregenerallyservedbyfewerairlines.E.Psychologistshavebeenabletodeterminenoconnectionbetweenthederegulationoftheairlineindustryandtheonsetofincreasedlevelsofairrage.16.Costcuttingandrestructuringhasallowedthemanufacturingcompanytoloweritsprojectedlossesforthesecondquarter,andtheyareforecastingaprofitbeforetheendoftheyear.A.hasallowedthemanufacturingcompanytoloweritsprojectedlossesforthesecondquarter,andtheyareforecastingB.hasallowedforthemanufacturingcompanytoloweritsprojectedlossesinthesecondquarterandtoforecastC.haveallowedthatthemanufacturingcompanycanlowertheprojectedlossesforthesecondquarter,andtoforecastD.haveallowedthemanufacturingcompanytoloweritsprojectedsecond-quarterlossesandtoforecastE.haveallowedforthemanufacturingcompanytolowertheprojectedlossesinthesecondquarter,aswellasforecasting17.Toordercertainplantsfromacatalog,itcosts$3.00perplant,plusa5percentsalestax,plus$6.95forshippingandhandlingregardlessofthenumberofplantsordered.IfCompanyCorderedtheseplantsfromthecatalogatthetotalcostof$69.95,howmanyplantsdidCompanyCorder?A.22B.21C.20D.19E.1818.Mr.JonesdrovefromTownAtoTownBinxhours.Onthereturntripoverthesameroute,

hisaveragespeedwastwiceasfast.Whichofthefollowingexpressesthetotalnumberofdrivinghoursfortheroundtrip?

19.IfthenumberofsquareunitsintheareaofcircleCistwicethenumberoflinearunitsinthecircumferenceofC,whatisthenumberofsquareunitsinthearea?A.4B.8C.4πD.8πE.16π20.Acertainrighttrianglehassidesoflengthx,y,andz,wherex

B.

C.

D.

E.21.SkilledblacksmithswhocouldforgeusefulitemsoutofironusedtoplayacentralroleinAmericanlife.Theonsetofindustrializationandthemassproductionofironproducts,however,havemadetheblacksmith'straditionalrolemostlyobsolete.Still,therewillalwaysbeajobavailableforagoodblacksmith.

Whichofthefollowing,iftrue,providesthemostsupportfortheconclusionthatajobwillalwaysbeavailableforagoodblacksmith?A.Manypeoplearewillingtopayconsiderablymorefortoolshand-craftedbyablacksmiththanfortoolscreatedbyamachine.B.Blacksmithscannotproduceironproductswiththespeedorconsistencyofmachines.C.Blacksmithstraditionallyapprenticedtoamasterblacksmithforsevenormoreyearsbeforeenteringbusinessindependently.D.ThecowboyneverwouldhaveconqueredtheWestwithoutthehorseshoescraftedbyblacksmiths.E.Asskilledcraftsmen,blacksmithstraditionallyservedascommunityleadersthroughoutNorthAmericaandEurope.22.Howmanyminuteswillittaketo

completelyfillawatertankwithacapacityof3,750cubicfeetifthewaterisbeingpumpedintothetankattherateof800cubicfeetperminuteandisbeingdrainedoutofthetankattherateof300cubicfeetperminute?A.3min.36see.B.6minutesC.7min.30sec.D.8minutesE.1,875minutes23.Howmanyintegersbetween1and16,inclusive,haveexactly3differentpositiveintegerfactors?

(Note:6isNOTsuchanintegerbecause6has4differentpositiveintegerfactors:1,2,3,and6.)A.1B.2C.3D.4E.624.Eventhoughtradinginivoryhasbeenoutlawedbyinternationalagreement,somepianomakersstilluseivory,oftenobtainedillegally,tocoverpianokeys.

Recently,expertshavedevisedasyntheticivorythat,unlikeearlierivorysubstitutes,hasfoundfavorwithconcertpianiststhroughouttheworld.Butbecausepianomakershaveneverbeenmajorconsumersofivory,thedevelopmentofthesyntheticivorywillthereforeprobablydolittletohelpcurbthekillingofelephants,fromwhosetusksmostnaturalivoryisobtained.

Whichoneofthefollowing,iftrue,mosthelpstostrengthentheargument?A.Mostpeoplewhoplaythepianobutarenotconcertpianistscannonethelesseasilydistinguishbetweenthenewsyntheticivoryandinferiorivorysubstitutes.B.Thenewsyntheticivorycanbemanufacturedtoresembleincolorandsurfacetextureanyofthevarioustypesofnaturalivorythathavecommercialuses.C.Othernaturalproductssuchasboneortortoiseshellhavenotproventobeacceptablesubstitutesfornaturalivoryinpianokeys.D.Themostcommonusefornaturalivoryisinornamentalcarvings,whichareprizednotonlyforthequalityoftheirworkmanshipbutalsofortheauthenticityoftheirmaterials.E.Itcostssignificantlylesstoproducethenewsyntheticivorythanitdoestoproduceanyoftheivorysubstitutesthatscientistshaddevelopedpreviously.25.

Ifofthetotalnumberofmarblesinthethreebagslistedinthetableaboveareblue,howmanymarblesarethereinbagQ?A.5B.9C.12D.23E.46第1卷參考答案一.歷年考點試題黑鉆版1.參考答案：E[解析]ArgumentConstruction

Situation

Somebiologistshavetried,unsuccessfully,tofindatheoreticallydefensibleaccountofwhatit

meansforsomethingtobearivingthing.Someofthesuggesteddefinitionsaretoobroad,because

theyincludethingsthatwewouldnotregardasriving.Tofindlifeonotherplanets,wemustnot

narrowourconceptionoflifebybasingitsimplyonthekindsoflifeencounteredonEarth.

Reasoning

Whichofthefivechoiceswouldbethelogicallymostappropriatecompletionoftheargument?The

argumentpointsoutthatlife-formselsewhereintheuniversemaybeverydifferentfromanyof

thelife-formsonEarth.Bothlife-formsonEarthandlife-formsdiscoveredelsewherewouldall

qualifyasmembersofaverylargeclass,theclassofallrife-forms.Takingrife-formsonEarth,

ameresubsetoftheclassofalllife-forms,asrepresentativeofalllife-formswouldbealogical

mistakeandwouldnotleadtosuccessindefiningwhatitmeansforsomethingtobealiving

thing.

A

Thiswouldnotinvolvealogicalmistakeliketheonealreadyidentified.

B

Thiswouldnotinvolvealogicalmistakecloselyresemblingtheonealreadyidentified.

C

Plantsarenotasubclassoftheclassofanimals,sothisdoesnotinvolvethelogicalmistakeoftakingasubclassasrepresentativeofalargerclass.

D

Thisdoesnotinvolvealogicalmistakecloselyresemblingtheonealreadydiscussed.

E

Correct.Thisinvolvesthelogicalmistakeoftakingtheclassofzebras,asubclassoftheclassofmammals,asrepresentativeoftheclassofmammals.Logically,itresemblestakingtheclassoflife-formsonEarthasrepresentativeoftheclassofalllife-forms.

ThecorrectanswerisE.2.參考答案：B[解析]Itisgiventhat,orx+y+z=9,orz=9+(-x-y).Itfollowsthatthegreatestpossiblevalueofzoccurswhen-x-y=-(x+y)hasthegreatestpossiblevalue,whichoccurswhenx+yhastheleastpossiblevalue.Becausexandyaredifferentpositiveintegers,theleastpossiblevalueofx+yoccurswhenx=1andy=2.Therefore,thegreatestpossiblevalueofzis9-1-2=6.3.參考答案：E[解析]根據(jù)奇數(shù)+偶數(shù)=奇數(shù)可知y+2和y+6都一定是奇數(shù)；2y是一個偶數(shù)，所以2y-1是一個奇數(shù)；因為3不能被2整除，y也不能被2整除，所以3y也不能被2整除，也即3y是一個奇數(shù)；因為奇數(shù)與偶數(shù)相間分布，所以3y+1一定是一個偶數(shù)。4.參考答案：E[解析]Sincethenumeratorofallofthefractionsintheanswerchoicesis0.03,theleastofthefractionswillbethefractionwiththegreatestdenominator.Thegreatestdenominatoris7.1,andsotheleastofthefractionsis5.參考答案：EIftheuniversityinitiatedlargecapitalexpenditureswiththeexpectationofsellingthebiotechstockat10timesitscurrentprice,thenoncethestockfallsinprice,theuniversitywillbeforcedtoraisethatmoneyfromsomewhereelse;inalllikelihood,thiswillharmtheuniversity'sfinances.6.參考答案：B[解析]在房主入睡以后發(fā)生的火災(zāi)很容易引起人員死亡，因此(B)選項不能解決本題論述中的明顯分歧；(A)選項表明床上抽煙一般不引起傷亡事件，因此抽煙人數(shù)顯著減少，但是死于家庭火災(zāi)的人數(shù)并沒有相應(yīng)地減少；(C)選項表明抽煙人數(shù)減少是由于不在床上抽煙的人不再抽煙所致，而這部分人又一般不引起家庭火災(zāi)，所以抽煙人數(shù)明顯減少，死于家庭火災(zāi)的人數(shù)并沒有顯著減少；(D)通過他因說明了死亡人數(shù)為什么沒相應(yīng)減少；(E)選項表明火災(zāi)發(fā)生的次數(shù)可能隨抽煙者的減少而減少，但隨人員密度的增加，每次死亡的人數(shù)卻增加了，所以死亡人數(shù)沒有隨抽煙人數(shù)的顯著下降而做相應(yīng)的下降。7.參考答案：B[解析]LetErepresentemploymentcosts,Srepresentsalarycosts,andFrepresentfringe-benefitcosts.ThenE=S+F.Anincreaseof3percentinsalarycostsanda5.5percentincreaseinfringe-benefitcostsresultedina3.5percentincreaseinemploymentcosts.Therefore1.03S+1.055F=1.035E.But,E=S+F,so1.03S+1.055F=1.035(S+F)=1.035S+1.035F.

Combiningliketermsgives(1.055-1.035)F=(1.035-1.03)Sor0.02F=0.005S.Then,.Thus,sinceE=S+F,itfollowsthatE=4F+F=5F.Then,FasapercentofEis8.參考答案：B[解析]根據(jù)題目中的定義可知，要使一個數(shù)的“l(fā)ength”最大，就必須使乘積等于它的質(zhì)數(shù)的值最小，而最小的質(zhì)數(shù)為2，又因為29=512，所以小于1,000的正整數(shù)的最大“l(fā)ength”為9。9.參考答案：E[解析]本題作為“完成段落”題型，重點要把握最后要補充的這一句話和段落前邊的論述是什么關(guān)系——是解釋前面所述，還是從前面得出結(jié)論，并且補充的這一句話要與段落前半部分有關(guān)，而段落前半部分告訴我們thedemocraticallyelectedpragmatistsaresensitivetotheelectorate，即當選官員受選民影響決定，那么補充的內(nèi)容應(yīng)與此吻合。(E)中的voters=electorate，stronglywish有perversity的意思，并且(E)指出是因為大多數(shù)選民并不希望有不同的政策而并非政府剛愎自用，所以(E)正確；(A)、(B)、(C)與“選民”無關(guān)，為無關(guān)答案；(D)只說明選民為什么選某些政治家，但我們討論的是政策決定的問題，所以(D)起不了任何作用。10.參考答案：BThisanswerundercutstheargumentthatcompaniescanboosttheirproductivitybystartingin-housechildcareprogramsbyshowingawayinwhichsuchprogramscanalsodecreaseproductivity.11.參考答案：B[解析]要支持這個洞穴藝術(shù)家畫的是他或她所熟悉的Chiru，就需要找一個選項表明在這個藝術(shù)家生活的那個時代，那個地方存在Chiru這種動物。從(B)選項所陳述的內(nèi)容，我們很容易推出Chiru這種動物至少在1.6萬年之前已經(jīng)在那個地方出現(xiàn)，比這個藝術(shù)家創(chuàng)作壁畫的時代早一千多年。由此分析可知(B)是正確答案。(A)和(D)對本題問題的假設(shè)構(gòu)成了反對；(C)中的“植物”與本題無關(guān)；(E)引入了與本文推理無關(guān)的新的比較，因此(A)、(C)、(D)、(E)均為錯誤選項。12.參考答案：E[解析]ArgumentEvaluation

Situation

Bumblebeesvisitbothlarkspuranddandelionsincertainmeadows.Astudyfoundthatmore

larkspurseedswereproducedinmeadowplotsinwhichbothlarkspuranddandelionsgrew

thaninsimilarplotsfromwhichalldandelionshadbeenremoved.Theresearchersinferredthat

dandelionsfacilitatelarkspurpollination.

Reasoning

Whatevidencewouldcastthemostdoubtontheinferencefromthestudy'sfindingstotheconclusionthat

dandelionsfacilitatelarkspurpollinationbyattractingmorepollinators?Theargumentassumesthat

theonlyrelevantdifferencebetweenthetwotypesofplotswaswhetherdandelionswerepresent.

Evidencethattheplotsdifferedinsomeotherwaythatcouldprovideaplausiblealternative

explanationofwhymorelarkspurseedswereproducedintheplotswithdandelionswouldweaken

theargument.

A

Thiswouldsuggestthatthelarkspurpollinationshouldhavebeenlowerintheplotswithdandelions,soitdoesnotprovideaplausiblealternativeexplanationforthestudy'sfindings.

B

Thisisfullycompatiblewiththeclaimthatthedandelionsattractedmorepollinatorstothemixedplots,anditwouldalsohelptosupporttheargument'sconclusionthatdandelionsfacilitatedlarkspurpollinationinthoseplots.

C

Althoughthissuggeststhatthemixedplotswon'tremainmixedforlong,itdoesnotprovideaplausiblealternativeexplanationforthestudy'sfindingthatlarkspurseedproductionwashigherinthemixedplots.

D

Theargumentisnotabouthowfitlarkspursareasaspecies,butaboutwhytheyproduceddifferentnumbersofseedsinthedifferentplots.

E

Correct.Thisprovidesaplausiblealternativeexplanationforwhylarkspurseedproductionwaslowerintheplotsfromwhichdandelionshadbeenremoved,sincediggingthemoutwouldhavedisturbedthesoil.

ThecorrectanswerisE.13.參考答案：B[解析]ArgumentEvaluation

Situation

Coloreddiamondsofatypethatcomprises2percentofallmineddiamondscanbetreatedsothattheyarenoteasilydistinguishablefrommorevaluable,naturallycolorlessdiamonds,butmanyaretoolowinqualityforthetreatmenttobeworthwhile.

Reasoning

Whydotheargument'spremisesnotjustifytheconclusionthatthevastmajorityofcolorlessdiamondssoldbyjewelersarenaturallycolorless?Sincethetypeofcoloreddiamondsthatcanbetreatedmakeuponly2percentofallmineddiamonds,andmanydiamondsofthattypearetoolowinqualityfortreatmenttobeworthwhile,thevastmajorityofmineddiamondsmustnotbetreatedtohavetheircolorremoved.However,wearenottoldwhatproportionofallmineddiamondsarenaturallycolorless.Naturallycolorlessdiamondsmaybefarrarereventhantheuncommondiamondsthathavebeentreatedtohavetheircolorremoved.Thus,forallwecantellfromthepassage,itcouldwellbethatmostcolorlessdiamondssoldbyjewelershavebeentreatedtoremoveallcolor.

A.Evenifsometypesofdiamondscommandhigherpricesforusesotherthanasgemstones,thetypesdiscussedinthepassageevidentlycommandhighenoughpricesasgemstonestobesoldassuchbyjewelers.

B.Correct.Theargumentdoesnotworkifnaturallycolorlessdiamondsarerarerthantreateddiamonds,astheymaybeforallwecantellfromtheinformationprovided.

C.Theargument'sconclusionisonlythatjewelerssellmorenaturallycolorlessdiamondsthandiamondstreatedtobecolorless.Whetherjewelerssellanycoloreddiamondsorothergemstonesisirrelevant.

D.Theargumentonlyconcernsthetypesofcolorlessdiamondssoldnow,notthetypesthatmaybesoldinthefutureifothertreatmentmethodsarediscovered.

E.Theargumentdoessuggestthisdifficultybutimpliesthatevensotherearetoofewtreateddiamondsavailableforjewelerstosellinplaceofnaturallycolorlessones.

ThecorrectanswerisB.14.參考答案：D15.參考答案：D16.參考答案：D[解析]Agreement;Idiom;VerbForm

Thepointofthesentenceistoexplainthetwomaineffectsofthechangesmadebythecompany.However,thesingularverbhasalloweddoesnotagreewiththecompoundsubjectcostcuttingandrestructuring,whicharefarmoreplausiblyunderstoodastwoactionsratherthanastwofacetsofasingleaction.Inprinciple,themanufacturingcompanycouldbeconstruedasplural(referringcollectivelytothedecisionmakersandspokespeoplewhoareprojectinglossesandforecastingaprofit),butthepluralpronountheydoesnotagreewiththeearlierits,whichtreatstheantecedentassingular.

A

Thesingularverbhasalloweddoesnotagreewiththecompoundsubjectcostcuttingandrestructuring,thepluralpronountheydoesnotagreewiththeintendedsingularantecedentcompany.

B

Thesingularverbhasalloweddoesnotagreewiththecompoundsubjectcostcuttingandrestructuring,allowedforisnotthecorrectidiom.

C

Allowedthatisnotthecorrectidiom;canlowerandtoforecastarenotgrammaticallyparallel.

D

Correct.Thesentenceusesthecorrectsubject-verbcombinationcostcuttingandrestructuringhaveallowed;thetwooccurrencesofthepronounitsagreewitheachotherintreatingtheirantecedentcompanyassingular;andthetwoeffectstolowerandtoforecastareparallelandidiomatic.

E

Allowedforisnotthecorrectidiom;tolowerandaswellasforecastingarenotparallel.

ThecorrectanswerisD.17.參考答案：C[解析]LettingxrepresentthenumberofplantsCompanyCboughtfromthecatalog,then,indollars,3.00xisthecostoftheplants,(0.05)(3.00x)isthesalestax,and6.95istheshippingandhandli