大学英语六级模拟试卷216

大学英语六级模拟试卷216

一、作文（本题共/题，每题上。分，共1分。）

1、Directions:Forthispart,youarcallowedthirtyminutestowriteacompositiononthe

topicItPaystoBeHonest.Youshouldwriteatleast150wordsaccordingtotheoutline

givenbelowinChinese:1.当前社会存在许多不诚实的现象。2.诚实利人利己，做

人应该诚实。

标准答案：ItPaystoBeHonestAsweallknow,honesty,asavirtueofmankind,has

beenchallengedinthemodernsocietyasweencountermereandmoredishonestthings

andpeople.Manypeoplearcasking,"DoIneedtobehonest'?Yes,weshouldbehonest.

First,honestyisessentiallyimportantinbuildinguptrustamongpeople.Ifwelosethis

moralstandard,theworldwouldbeoutoforderbecausethereisnotrustamongpeople.

Therefore,itiseveryperson'sresponsibilitytokeepthisvirtuesothatthesocietywillnot

fallapart.Secondly,（obehonestbringsbenefitstopeoplearoundyou.Yourhonestywill

helpyourco-workersandconpanyworksuccessfully.Yourspouseandyourchildren

willbehappyandfeelsafe.Yourfriendswillalwayscometoyouwhentheyneedhelp.

Finally,youyourselfwillhenefilfrombeinghonest.Peoplewillrespect,trustandlove

you.Youwillbeblessedbyhavingastablemarriage,aprosperouscareer,manyfriends

andmoreimportantly,apeacefulheart.Itpaystobehonest,butitisdefinitely

worthwhilebecauseyouwillgetmorethanwhatyoupay.Yourlifewillbemeaningfulas

youwillbeappreciatedandrememberedasanhonestperson.

知识点解析：暂无解析

二、快速阅读理解（本题共70题，每题分，共70

分。）

AcidRainWhatIsAcidRain?"Acidrain"isabroadtermusedtodescribeseveralways

thatacidsfalloutoftheatmosphere.Amoreprecisetermisaciddeposition,whichhas

twoparts:wetanddry.Wetdepositionreferstoacidicrain,fog,andsnow.Asthisacidic

waterflowsoverandthroughtheground,itaffectsavarietyofplantsandanimals.The

strengthoftheeffeclsdependsonmanyfactors,includinghowacidicthewaleris,the

chemistryandbuffering（隔离）capacityofthesoilsinvolved,andthetypesoffish,trees,

andotherlivingthingsthatrelyonthewater.Drydepositionreferstoacidicgasesand

particles.Abouthalfoftheacidityintheatmospherefallsbacktoearththroughdry

deposition.Thewindblowstheseacidicparticlesandgasesontobuildings,cars,homes,

andtrees.Dry-depositedgasesandparticlescanalsobewashedfromtreesandother

surfacesbyrainstorms.Whenthathappens,therunoffwateraddsthoseacrestotheacid

rain,makingthecombinationmoreacidicthanthetailingrainalone.HowDoWe

MeasureAcidRain?Acidrainismeasuredusingascalecalled"pH”.Thelowera

substance'spH,(hemoreacidicitis.PurewaterhasapHof7.0.Normalrainisslightly

acidicbecausecarbondioxidedissolvesintoit,soithasapHofabout5.5.Asoftheyear

2000,themostacidicrainfallingintheU.S.hasapHofabout4.3.EffectsofAcidRain

Acidraincausesacidification(酸化)oflakesandstreamsanccontributes(odamageof

treesathighelevations(forexample,redsprucetreesabove2,000feet)andmany

sensitiveforestsoils.Inaddition,acidrainacceleratesthedecayofbuildingmaterialsand

paints,includingirreplaceablebuildings,statues,andsculpturesthatarepartofour

nation'sculturalheritage.PriortofailingtotheEarth,SO2andNOxgasesandtheir

particulatematterderivatives,sulfatesandnitratescontributetovisibilitydegradationand

harmpublichealth.WhatSocietyCanDoAboutDeposition?Therearcseveralwaysto

reduceaciddeposition,rangingfromsocietalchangestoindividualaction.•Understand

AcidDeposition'sCausesandEffectsTounderstandaciddeposition'scausesandeffects

andtrackchangesintheenvironment,scientistsfromEPA,stategovernments,and

academiesstudyacidificationprocesses.Theycollectairandwatersamplesandmeasure

(hemforvariouscharacteristicslikepHandchemicalcomposition,andtheyresearchthe

effectsofaciddepositiononhuman-madematerialssuchasmarbleandbronze.Finally,

scientistsworktounderstandtheeffectsofsulfurdioxide(SO2)andnitrogenoxides

(NOx)—thepollutantsthatcauseaciddepositionandfinepanicles—onhumanhealth.To

solvetheacidrainproblem,peopleneedtounderstandhowacidraincausesdamageto

theenvironment.Theyalsoneedtounderstandwhatchangescouldbemadetotheair

pollutionsourcesthatcausetheproblem.Theanswerstothesequestionshelpleaders

makebetterdecisionsabouthowtocontrolairpollutionandthereforehowtoreduce-or

eveneliminate—acidrain.Sincetherearemanysolutionstotheacidrainproblem,

leadershaveachoiceofwhichoptionsorcombinationsofoptionsarcbest.Thenext

sectiondescribessomeofthestepsthatcanbetakentoreduce,oreveneliminate,theacid

depositionproblem.•CleanUpSmokestacks(烟囱)andExhaustPipesAlmostallofthe

electricitythatpowersmodernlifecomesfromburningfossilfuelslikecoal,naturalgas,

andoil.Aciddepositioniscausedbytwopollutantsthatarereleasedintotheatmosphere,

oremitted,whenthesefuelsarcburned:sulfurdioxide(SO2)andnitrogenoxides(NOx).

CoalaccountsformostU.S.sulfurdioxide(SO2)emissionsandalargeportionofNOx

emissions.Sulfurispresentincoalasanimpurity,anditreactswithairwhenthecoalis

burnedtoformSO2.Incontrast,NOxis(brinedwhenanyfossilfuelisburned.Thereare

severaloptionsforreducingSO2emissions,includingusingcoalcontaininglesssulfur,

washingthecoal,andusingdevicescalledscrubberstochemicallyremovetheSO2from

(hegasesleavingthesmokestack.Powerplantscanalsoswitchfuels;forexample

burningnaturalgascreatesmuchlessSO2thanburningcoal.Certainapproacheswill

alsohaveadditionalbenefitsofreducingotherpollutantssuchasmercuryandcarbon

dioxide.Understandingthese"co-benefits"hasbecomeimportantinseekingcost-

effectiveairpollutionreductionstrategies.Finally,powerplantscanusetechnologiesthat

don'tburnfossilfuels.Eachcftheseoptionshasitsowncostsandbenefits,however;

thereisnosingleuniversalsolution.,UseAltemativeEnergySourcesThereareother

sourcesofelectricitybesidesfossilfuels.Theyinclude:nuclearpower,hydropower,wind

energy,geothermalenergy,andsolarenergy.Ofthese,nuclearandhydropowerareused

mostwidely;wind,solar,andgeothermalenergyhavenotyetbeenharnessedonalarge

scaleinthiscountry.Therearcalsoalternativeenergiesavailabletopowerautomobiles,

includingnatural-gaspowcrcdvehicles,battery-poweredcars,fuelcells,and

combinationsofakernaiiveandgasolinepoweredvehicles.Allsourcesofenergyhave

environmentalcostsaswellasbenefits.Sometypesofenergyaremoreexpensiveto

producethanothers,whichmeansthatnotallAmericanscanaffordalltypesofenergy.

Nuclearpower,hydropower,andcoalarcthecheapestformstoday,butchangesin

technologiesandenvironmentalregulationsmayshiftthatinthefuture.Allofthese

factorsmustbeweighedwhendecidingwhichenergysourceiousetodayandwhichto

investinfortomorrow.RestoreaDamagedEnvironmentAciddepositionpenetrates

deeplyintothefabricofanecosystem,changingthechemistryofthesoilaswellasthe

chemistryofthestreamsandnarrowing,sometimestonothing,ihespacewherecertain

plantsandanimalscansurvive.Becausetherearesomanychanges,ittakesmanyyears

forecosystemstorecoverfromaciddeposition,evenafteremissionsarereducedandthe

rainbecomesnormalagain.Forexample,whilethevisibilitymightimprovewithindays,

andsmallorchemicalchangesinstreamsimprovewithinmonths,chronicallyacidified

lakes,streams,forests,andsoilscantakeyearstodecadesorevencenturies(inthecase

ofsoils)toheal.However,therearesomethingsthatpeopledotobringbacklakesand

streamsmorequickly.Limestone(石灰石)orlime(anaturally-occurringbasic

compound)canbeaddedtoacidiclakesto"cancelout"theacidity.Thisprocess,called

liming,hasbeenusedextensivelyinNorwayandSwedenbutisnotusedveryoftenin(he

UnitedStates.Limingtendstobeexpensive,hastobedonerepeatedlytokeepthewater

fromreturningtoitsacidiccondition,andisconsideredashort-termremedyinonly

specificareasratherthananefforttoreduceorpreventpollution.Furthermore,itdoesnot

solvethebroaderproblemsofchangesinsoilchemistryandforesthealthinthe

watershed,anddoesnothingtoaddressvisibilityreductions,materialsdamage,andrisk

tohumanhealth.However,limingdocsoftenpermitfishtoremaininalake,soitallows

thenativepopulationtosurviveinplaceuntilemissionsreductionsreducetheamountof

aciddepositioninthearea.LooktotheFutureAsemissionsfromthelargestknown

sourcesofaciddeposition—powerplantsandautomobiles—arereduced,EPAscientists

andtheircolleaguesmustassessthereductionstomakesuretheyareachievingthe

resultsCongressanticipated.Iftheseassessmentsshowthataciddepositionisstill

harmingtheenvironment,theymayconsideradditionalemissionsreductionsfrom

sourcesthathavealreadybeencontrolled,ormethodstoreduceemissionsfromother

sources.Theymayalsoinvestinenergyefficiencyandalternativeenergy.TakeActionas

IndividualsItmayseemlikethereisnotmuchthatoneindividualcandotostopacid

deposition.However,likemanyenvironmentalproblems,aciddepositioniscausedbythe

cumulativeactionsofmillionsofindividualpeople.Therefore,eachindividualcanalso

reducetheircontributiontotheproblemandbecomepartofthesolution.Oneofthefirst

stepsistounderstandtheproblemanditssolutions.Individualscancontributedirectlyby

conservingenergy,sinceenergyproductioncausesthelargestportionoftheacid

depositionproblem.Forexample,youcan:•Turnofflights,computers,andother

applianceswhenyou'renotusingthem.•Useenergyefficientappliances:lighting,air

conditioners,heaters,refrigerators,washingmachines,etc.•Onlyuseelectricappliances

whenyouneedthem.Keepyourthermostatat680Finthewinterand72°Finthe

summer.Youcanmmitevenlowerinthewinterandhigherinthesummerwhenyouare

awayfromhome.•Insulate(隔SQyourhomeasbestyoucar.•Carpool(合伙使用权用

汽车),usepublictransportation,orbetteryet.walkorbicyclewheneverpossible.•Buy

vehicleswithlowNOxemissions,andmaintainallvehicleswell.,Bewell-informed.

2、Thehigherasubstance^pH,themoreacidicitis.

A、Y

B、N

C、NG

标准答案：B

知识点解析：暂无解析

3、Acidrainmaydamagetrees,soilsandacceleratethedecayofbuildings.

A、Y

B、N

C、NG

标准答案：A

知识点解析：暂无解析

4、Iftakingpropersteps,wecaneliminateaciddeposition.

A、Y

B、N

C、NG

标准答案：A

知识点解析：暂无解析

5、Tosolveacidrainproblems,wemusthaveexpertsdevelophightechnology.

A、Y

B、N

C、NG

标准答案：C

知识点解析：暂无解析

6、Amoreprecisetermforacidrainis,whichhasIwoparts:wetanddry.

标准答案：aciddeposition

知识点解析：暂无解析

7、Thescaleusedtomeasureacidrainiscalled.

标准答案：pH

知识点解析：暂无解析

8、Thetwopollutantsthatcauseaciddepositionareandnitrogenoxides(NOx).

标准答案:sulfurdioxide(orSO2)

知识点解析：暂无解析

9、Amongthealternativeenergysources,,andcoalarethecheapestformstoday.

标准答案：nuclearpower,hydropower

知识点解析：暂无解析

10>InNorwayandSweden,(heprocesscalledhasbeenusedextensivelyto

"cancelout"(heacidityinacidiclakes.

标准答案：liming

知识点解析：暂无解析

11、Individualscancontributedirectlytosolvingtheproblemofaciddeposition

标准答案：conservingenergy

知识点解析：暂无解析

三、听力短对话(本题共8题，每题上0分，共8分。)

12、

A、2.

B、3.

C、6.

D、9.

标准答案：C

知识点解析：暂无解析

13、

A、Inatheater.

B、Inaclinic.

C、Atabank.

D^Inaplane.

标准答案：A

知识点解析：暂无解析

14、

A^Akindoffeeling.

B,Akindofseasoning.

C、Theseafoodbanquet.

D、TomMarkham'snewhouse.

标准答案：B

知识点解析：暂无解析

15、

A^Hethinksthepantsfithimatthewaist.

B、Hethinksthepantsarcalittletightonthehips.

C、Hethinksthepriceisreasonable.

D、Hedoesn'tfeellikebuyingthepants.

标准答案：D

知识点解析：暂无解析

16、

A、Tolookforthelosttextbookinthelibrary.

B、TocallLost-and-Foundfirstbeforebuyinganewone.

C、Tobuyanewtextbooksincethefinalexamiscomingsoon.

D、Toborrowatextbookonwhichthere'rcnotestakenalready.

标准答案：B

知识点解析：暂无解析

17、

A、ThemanboughtthewatchlastSunday.

B、Themanagercangivemoneybacktotheman.

C、Thewomanwillspeaktothemanageraboutthematter.

D、Thewaterproofwatchwasboughtintheperiodofpromoiion.

标准答案：D

知识点解析：暂无解析

18、

A、Togototheoverseas-students'housingofficeforhelp.

B、TocheckthelistoftheavailableapartmentontheInternet.

C、Toseedifferentlandladiessoastofindasatisfyingapartment.

D、Tocheckoutanapartmentforhisparents.

标准答案：A

知识点解析：暂无解析

19、

A、Thewoman'selderlyauntisn'teasy-going.

B、Thewoman'selderlyaunthatesnoisebutlikesketchup.

C、Thewomanhadbetteradjustherattitudetowardsthematter.

D^Thewomanhadbeltersendheraunttosomeotherplacelolive.

标准答案：C

知识点解析：暂无解析

四、听力长对话（含3小题）（本题共3题，每题1.0

分,共3分。）

20、

A^Bossandsecretary.

B、Customerandsalesman.

C、Doctorandpatient.

D^Husbandandwife.

标准答案：B

知识点解析：暂无解析

21、

A、$15.

B、$50.

C、$35.

D、$20.

标准答案：D

知识点解析；暂无解析

22、

A、ThewomanhasboughtaT-shirtasherhusband'sbirthdaypresentlastmonth.

B、Thewomanlikesthedarkcolorverymuch.

C、Thewomanspends$35tobuythepresentsforherhusbandanddaughter

D、Thewomancanrubandwringthesilkwhenshewashesit.

标准答案：C

知识点解析：暂无解析

五、听力长对话（含4小题）（本题共4题，每题7.0

分,共4分。）

23、

A、ItexistsclosetothesurfaceoftheEarth.

B、Itisacomponentofsmogandaharmfulsubstance.

C^Itisakindofyellowgas.

D^Itisformedthroughacomplexreaction.

标准答案：C

知识点解析：暂无解析

24、

A、Ithurtsoureyes.

B、1（hurtsourskin.

C^Itisharmfultoourrespiratorysystem.

D、Itcancausecancers.

标准答案：C

知识点解析：暂无解析

25、

A、Spring.

B、Summer.

C、Autumn.

D、Winter.

标准答案：B

知识点解析：暂无解析

26、

A^Ozoneisanextremelyinactivegas.

B、Ozoneonlyexistsintheupperatmosphere.

C、Ground-levelozoneiscloselyrelatedtopeople'shealth.

D^Childrenbreathemoreairperpoundofbodyweight（hanadults.

标准答案：D

知识点解析：暂无解析

六、听力短文（含3小题）（本题共6题，每题1.0

分，共6分。）

27、

A^Theman^professor.

B、Theman'sroommate.

C、Aneighbor.

D、Theman'sbrother.

标准答案：B

知识点解析：判断推理题。由文中的相关词“movein,apartment,aroomchange^^

可推断出他们是同屋室友。

28、

A^Heistoosloppy.

B、HeborrowsColin'sthings.

C、Hebringsguestsovertotheapartment.

D、Hedoesn'tusethekitchenenough.

标准答案：C

知识点解析:细节考察题。原文中说“Colinstartsyellingatmeabouthowmyfriends

arealwayscomingoverwhenhehasalotofworktodo”,Colin说在他很忙的时候叙

述者总有朋友到宿舍来，由此可得出答案C。

29、

A、TrytotalktoColin.

B、Gohomeforaweek.

C、Waittill（heendofthisweek.

D、Havearoomchangeimmediately.

标准答案：C

知识点解析：判断推理题。原文说宿舍管理老师（headresident）答应跟Colin谈一

谈，“Iwillseehowitgoes.IfIstillhaveaproblemattheendofweek,Iwillaskfora

roomchange.”所以叙述者将等到周末，如果无法解决问题，他将要求换宿舍。

30、

A、Kingsandqueens,princesandprincesses,andlordsandladiesbuiltcastlesinorder

togetmoreland.

B、Aroundtheoutsideofacastle,amoatwasdug,whichwasoftenfilledwithwater.

C、Acastlewasbuiltbehindathickandhighstonewall,whichwasstrongenoughto

standthepossibleattackofenemies.

D、Ifadrawbridgewaspulledup,therewasnowayforpeopletoenterthecastle.

标准答案：A

知识点解析：细节考察题。根据第一段最后一句话Toproleci【hemselves,ihey

startedbuildinghugehomesoutofstone.Theycalledtheirhomescastles.得知他们建

造城堡的原因是为了自我保护，所以答案是A。

31、

A、Theylivedaluxuriouslifeand（heirdietwasverydelicate.

B、Theylivedahighlycivilizedcourtlife.

C、Theylivedaprimitivelifeandtheirtablemannerwasoftenrude.

D、Theylivedacomparativelyluxuriousbutnotsocivilizedlife.

标准答案：D

知识点解析：细节考察题。根据最后两段关于他们饮食情况的描述，得知他们很奢

侈，但举止很不文明，所以选择答案D。

32、

A、Castles'structureandtheeatinghabitinthem.

B、Castles,structureandthepeoplewholivedinthem.

C、Castles'structureandthelifeinthem.

D^Whypeoplebuiltcastlesandtheirstructure.

标准答案：C

知识点解析：综合分析题。根据全文谈论的内容，本段材料主要讲述中世纪欧洲人

所居住的城堡的结构以及他们的生活，因此选择答案C。

七、听力短文（含4小题）（本题共4题，每题7.0

分，共4分。）

33、

A、Callonpeopletoprotectsharks.

B、Pointoutthelivingenvironmentofsharks.

C、Explainwhythesharksaredangerous.

D^Anintroductiontosharks.

标准答案：D

知识点解析：主旨题。本文是围绕着鲨鱼的生活习性展开。A,C与本文无关，B

只指出了一方面。

34、

A^Bygoodsenseofwaterwavesmadebyquarries.

B、Bygoodsenseofsmellandelectricalmagneticpower.

C、Bygoodsenseoflight.

D^Dygoodsenseofblood.

标准答案：B

知识点解析:细节考察题。相关句子："Sharksdonothavehones,andasharkhasan

extremelygoodsenseofsmell.Itcanfindsmallamountsofsubstancesinthewater,

suchasblood»bodyliquidsandchemicalsproducedbyanimals.Sharksalsosense

electricalandmagneticpowerlinkedtonervesandmusclesoflivinganimals.These

powerfulsenseshelpthemfindtheirfood.“可以看出冷值可；敏锐的嗅觉和电磁感觉

来捕食猎物。

35、

A、Bonestructure.

B、Smellability.

C、Birthmode.

D、Recoverabilityagainstdisease.

标准答案：C

知识点解析：细节考察题。相关句子："Somesharkscarrytheiryounginsidetheir

bodieslikehumansdo.”可以看出部分鲨鱼的生育方式与人类一样。

36、

A^Theirtastymeat.

B、Theprincipleoftheirdefensesystemagainstdisease.

C、Theirsolidskin.

D、Theprincipleoftheirbirthmodes.

标准答案：B

知识点解析：客观事实题。相关句子："Medicalresearcherswantlolearnmoreaboul

theshark'sbodydefensesystemagainstdisease.”可以看出人类渴望通过研究鲨鱼的

抗病机理以期对人类有帮助。

八、听力复合式听写（本题共〃题，每题7.0分，共

〃分。）

Iheardalovelystoryaboutsomebodywhotook[Bl]onherhusband-A

youngmanpickedupacopyoftheEveningStandardonedayandhewas[B2]

throughtheadsforcars.Hesawthiscar...aRollsRoycefouryearsold[B3]for

£25...soheassumed,obviously,thatitwasa[B4]mistake,butjustincase,he

rangupthephonenumberinthead.Awomanansweredthephone,andhesaid"You've

gotaRollsRoyce...advertisedfor£25,isthatright?"andshesaid"yes."Sohesaid

"Well,couldIcomeandseeit?"andshegavehimthe[B5]andhewenttosee

it,not[B6]believingitobviously;butontheotherhandnotwantingtomissan

[B7].Sosheshowedhimthecaranditwasa...four-year-oldRollsRoycein

[B8]condition,notamarkonit.Hestartedthecaranditworkedperfectly

well.And...soitwaswonhabout£40,000...Andsohe...sonofheldhisbreathandthen

hesaidtothewoman"Erm...andyouwanttosellthiscarfor£257"Shesaid"Yes."

[B9].Shesaid"That'sallright.AllIwantis£25."So

veryquicklyhegotouthiswallet,paidherthe£25.[BIO]

.signedthebillofsale,andgotintothecar.Because

hecouldn'tbearnotknowing,heaskedjustbeforehedroveaway:"Butwhy?Whyarc

yousellingthisveryvaluablecarfor£25?""It'squitesimple,"thewomansaid.[Bl1]

37、[Bl]

标准答案：revenge

知识点解析：暂无解析

38、[B2]

标准答案:glancing

知识点解析：暂无解析

39、[B3]

标准答案：advertised

知识点解析：暂无解析

40、[B4]

标准答案:printing

知识点解析：暂无解析

41、[B5]

标准答案：address

知识点解析：暂无解析

42、[B6]

标准答案：quite

知识点解析：暂无解析

43、[B7]

标准答案：opportunity

知识点解析：暂无解析

44、[B8]

标准答案：perfect

知识点解析：暂无解析

45、[B9]

标准答案：Andhewasateniblyhonestman,sohe.raid"It'sprobablyworthalittle

morethanthat,youknow."

知识点解析：暂无解析

46、[BIO]

标准答案：Shegavehimthedocumentsrelatingtothecar,whichwereallperfectly

legitimateasfarashecouldtell

知识点解析：暂无解析

47、[Bll]

标准答案："Myhusbandleftmeandhe'slivingwithhissecretary.Buthewrotetome

andsaid,'wouldyousellthecarandsendmewhatevermoneyyougetforit?'"

知识点解析：暂无解析

九、阅读（常规阅读理解）（本题共7。题，每题1.0

分,共70分。）

Acountryissaidtobecomemoreurbanizedasitscitiesgrowinnumber,itsurban

populationsincreaseinsize,andtheproportionofitspopulationlivinginurbanareas

rises.Thedegreeofurbanizationvariesacrosstheworldbutgenerallyreflectsthewealth

ofindividualcountries.Therich,industrializedcountriestendtobethemosthighly

urbanized.IntheNetherlands,fbrexample,89percentof（hepopulationisurban,

comparedtoonly13percentinEthiopia,amuchpoorercountry.Inrecenthistory,the

degreeofurbanizationhasbe?nrelativelylowinAfricaandAsiacomparedtoEurope

andNorthAmerica.However,asaresultoflarge-scalemigrationfromruralareasanda

naturalincreaseintheurbanpopulationsthemselves,thepopulationsofcitiesinthe

developingworldhavebeengrowingrapidly.ThepopulationofCairo,fbrexample,has

tripledinthelast40years,andmorethanhalfofAfrica'speopleareexpectedtobeliving

incitiesby2020.Similarly,theurbanshareofthepopulationinChinahasrisenfrom

aboutoneinfivein1960tonearlyhalftoday.Oneofthemostnoticeablefeaturesof

urbangrowthinthe20thcenturyhasbeentherapidincreaseinthenumberofverylarge

cities.Before1800,citieswithmorethanamillioninhabitantswererare.Sincethen,

however,thenumberofsuchcitieshasrisensteadily.In1900therewereatleast13cities

withmorethanamillioninhabitants,andby1950thenumberhadgrownto68.By2000

iherewillbealleast250citiesofmorethanamillion—manyofwhichwillbeinAsia,

especiallyinIndiaandChina.Evenacityofafewmillionpeopleisdwarfedbytheurban

giantswithpopulationsexceeding10million.According(ovariousestimates,(heremay

be20ormoreofthesegiganticmetropolitanareasalready.MostareinAsia:Tokyo,

Seoul,Osaka,Shanghai,Mumbai(Bombay),Beijing,Calcutta,Jakarta,Tianjin,Karachi,

Delhi,andManila.TheothergiantsarcNewYork,SaoPaulo,MexicoCity,LosAngeles,

Moscow,BuenosAires,RiodeJaneiro,andCairo.Incomingyears,explosivegrowthin

citiesofthedevelopingworldsuchasLagosandSantaFedeBogotawillalmost

certainlypropeltheminto(hisgroup.Bytheyear2020,severalcitiesareexpectedto

havepopulationsofmorethan20million.Suchlargeconcentrationsofpeoplepose

immenseenvironmentalproblems.InMexicoCity,forexample,one-quarterofthe

populationhasnoaccesstorunningwater,andoneinfivehousesisnotconnectedlothe

seweragesystem.Locatedinavalley,thecitysufferssobadlyfromairpollutionfrom

motorvehiclesthatthecitycentermustperiodicallybeclosedtotraffic.MexicoCity's

problemsarereplicatedinmostotherlargecitiesinthedevelopingworld,andtoalesser

degreeinthelargecitiesofindustrializedcountriesaswell.

48、Acountry'surbanizationcanbeseenfromitsincreasein.

A、wealth

B、population

C、thenumberofcities

D、urbanareas

标准答案：C

知识点解析：暂无解析

49>Whichofthefollowingisachangeincitydevelopmentinthe20thcentury?

A、MorethanhalfofAfricanpopulationwillliveincities.

B、ManycitiesinAsiawillhavemorethan20millioninhabitants.

C、Citiesinthedevelopingworldwillbeevenlarger.

D^MorecitiesinAsiahavemorethanonemillionpeople.

标准答案：D

知识点解析：暂无解析

50、InParagraph3,theauthormainlyemploystoillustratehispoint.

A、examples

B、figures

C、comparisons

D^definitions

标准答案：B

知识点解析：暂无解析

51、Theworddwarf(Line1,Para.4)means.

A、causetoappearsmallerbycontrast

B、preventfromgrowingtofullsize

C、causetoappearlessimportantbycontrast

D^preventfromgrowinglarge

标准答案：A

知识点解析：暂无解析

52^Itcanhelearnedfromthelastparagraphthat.

A、motorvehiclesarethemaincauseforairpollutioninMexico

B、there'sashortageofwatersupplyandhousesinMexico

C、airpollutionisseriousinMexicobecauseofitslocation

D^urbanizationleadstoenvironmentalproblemsinbothdevelopinganddeveloped

countries

标准答案：D

知识点解析：暂无解析

NewresearchfromVanderbiltUniversitysuggeststhatwecanremembermorefacesthan

otherobjectsandthatfaces"stick"thebestinourshort-termmemory.Thereasonmaybe

thatourexpertiseinrememberingfacesallowsustopackagethembetterformemory.

"Ourresultsshowthatwecanstoremorefacesthanotherobjectsinourvisualshort-term

memory,"Gauthier,associateprofessorofpsychologyandthestudy'sco-author,said.

"Webelievethishappensbecauseofthespecialwayinwhichfacesareencoded."Kim

Curby,thestudy'sprimaryauthorandapost-doctoralresearcheratYaleUniversity,

likenssuchencodingtopackingasuitcase."Howmuchyoucanfitinahagdependson

howwellyoupackit,"shesaid."Inthesameway,ourexpertisein'packaging'faces

meansthatwecanremembermoreofthem."CurbyandGauthier'sresearchhaspractical

implicationsforthewayweusevisualshort-termmemoryorVSTM."Beingabletostore

morefacesinVSTMmaybeveryusefulincomplexsocialsituations,"Gauthiersaid.

"ThisopensupthepossibilityoftrainingpeopletodevelopsimilarlysuperiorVSTMfbr

othercategoriesofobjects,"Curbyadded.Short-termmemoryiscrucialtoour

impressionofacontinuousworld,servingastemporarystorageforinformationthatwe

arecurrentlyusing.Forexample,inorder(ounderstandthissentence,yourshort-term

memorywillremember(hewordsinthebeginningwhileyoureadthroughto(heend.

VSTMisacomponentofshort-termmemorythathelpsusprocessandbrieflyremember

imagesandobjects,ratherthanwordsandsounds.VSTMallowsustorememberobjects

fbrafewseconds,butitscapacityislimited.CurbyandGauthier'snewresearchfocuses

onwhetherwecanstoremorefacesthanotherobjectsinVSTM,andthepossible

mechanismsunderlyingthisadvantage.Studyparticipantsstudieduptofivefacesona

screenfbrvaryinglengthsoftime(uptofourseconds).Asinglefacewaslaterpresented

andparticipantsdecidedifthiswasafacethatwaspartoftheoriginaldisplay.Fora

comparison,theprocesswasrepeatedwithotherobjects,likewatchesorcars.Curbyand

Gauthierfoundthatwhenparticipantsstudiedthedisplaysforonlyabriefamountoftime

(halfasecond),theycouldstorefewerfacesthanobjectsinVSTM.Theybelievethisis

becausefacesaremorecomplex(hanwatchesorcarsandrequiremoretimetobe

encoded.Surprisingly,whenparticipantsweregivenmoretimetoencodetheimages

(fourseconds),anadvantageforfacesoverobjectsemerged.Theresearchersbelievethat

ourexperiencewithfaces