请阅读Passage2，完成此题。 Passage2 Untiladecadeortwoago,thecentersofmanyWesterncitieswereemptyingwhiletheiredgeswerespreading.Thiswasnotforthereasonsnormallycited.Neitherthecarnorthemotorwaycausedsuburbansprawl,althoughtheyspeditup:citieswerespreadingbeforeeithercamealong. Norwastheflighttothesuburbscausedbyracism.Whitesfledinner-cityneighborhoodsthatwerebecomingblack,buttheyalsofledonesthatwerenot.Planningandzoningrulesencouragedsprawl,asdidtaxbreaksforhomeownership--butcitiesspreadregardlessofthese.Therealcausewasmassaffluence.Aspeoplegrewricher,theydemandedmoreprivacyandspace.Onlyafewcouldaffordthatincitycenters;therestmovedout. Thesameprocessisnowoccurringinthedevelopingworld,butmuchmorequickly.Thepop-ulationdensityofmetropolitanBeijinghascollapsedsince1970,fallingfrom425peopleperhectareto65.Indiancitiesarefollowing;Brazil'sareahead.Andsuburbanizationhasalongwaytorun.BeijingisnowaboutascrowdedasmetropolitanChicagowasatitsmostcloselypacked,inthe1920s.SincethenChicago'sdensityhasfallenbyalmostthree-quarters. Thisiswelcome.Romanticnotionsofsociable,high-densityliving--notionspushed,forthemostpart,bypeoplewhothemselvesoccupyratherspaciousresidences--ignorethesqualorandlackofprivacytobefoundinKinshasa,Mumbaiortheothercrowdedcitiesofthepoorworld. Manyofthemarefartoodensefordignifiedliving,andneedtospreadout. TheWesternsuburbstowhichsomanyaspirearehealthierthantheirdetractorssay.ThemodernStepfordsarenolongerwhitemonocultures,butthatisprogress.ForeveryFergusontherearemanyAmericansuburbsthathavequietlybecomeblack,HispanicorAsian,orablendofevery-one.PicaresqueaccountsofdecayoverlookthefactthatAmerica'ssuburbsarehalfascriminalandalittlemorethanhalfaspoorascentralcities.Evenasurbancentersrevive,moreAmericansmovefromcitycentretosuburbthangotheotherway. ButtheWesthasalsomademistakes,fromwhichtherestoftheworldcanlearn.Thefirstlessonisthatsuburbansprawlimposescostsoneveryone.Suburbanitestendtousemoreroadsandconsumemorecarbonthanurbanites(thoughperhapsnotasmuchasdistantcommutersforcedoutbygreenbelts).Butthisdamagecanbealleviatedbyacarbontax,bytollroadsandbychargingforparking.ManycitiesintheemergingworldhavefollowedthefoolishAmericanpracticeofre-quiringpropertydeveloperstoprovideacertainnumberofparkingspacesforeverybuilding--somethingthatmakescommutingbycarmuchmoreattractivethanitwouldbeotherwise.Scrap-pingthemwouldgivepublictransportachance. Thesecondisthatitisfoolishtotrytostopthespreadofsuburbs.Greenbelts,themostef-fectivemethodfordoingthis,pushuppropertypricesandencouragelong-distancecommuting.ThecostofhousinginLondon,alreadyastronomical,wentupby19%inthepastyear,reflectingnotjustthecity'sstrongeconomybutalsotheimpossibilityofbuildingonitsedges.TheinsistenceonbigminimumlotsizesinsomeAmericansuburbsandruralareashasmuchthesameeffect.Citiesthattrytopreventgrowththroughgreenbeltsoftenendupweakeningthemselves,asSeoulhasdone. Awiserpolicywouldbetoplanforhugeexpansion.Acquirestripsoflandforroadsandrail-ways,andchunksforparks,beforethecitysprawlsintothem.NewYork's19th-centurygovernorsdecidedwhereCentralParkwasgoingtogolongbeforethecityreachedit.NewYorkwentontodevelopinawaythattheycouldnothaveimagined,buttheparkisstillthere.Thisisnotthestatecontrolofthenew-townplanner--thatconfidentsoulwhobelievesheknowswherepeoplewillwanttoliveandwork,andhowtheywillgetfromonetotheother.Itistherealismneededtomanagetheinevitable.AmodeloflivingthathasbroadlyworkedwellintheWestisspreading,adaptingtolocalconditionsasitgoes.WeshouldalllookforwardtothetimewhenChineseandIndianteenagerswritesulkysongsabouttheappallingdullnessofsuburbia. Forwhichofthefollowingreasonsdidthewestmoveoutofcities? 查看材料
A.They didn't need to pay higher taxes when living in suburbs. B.Car industry rapidly developed and motorways swiftly emerged. C.They discriminated against the black people living in city centers. D.The richer they grew, the more demand they had on privacy and space.正确答案D
