2018年6月大学英语六级听力常考时文：Suburbanization思维导图

Ifby"suburb"ismeantanurbanmarginthatgrowsmorerapidlythanitsalreadydevelopedinterior,theprocessofsuburbanizationbeganduringtheemergenceoftheindustrialcityinthesecondquarterofthenineteenthcentury.Beforethatperiodthecitywasasmallhighlycompactclusterinwhichpeoplemovedaboutonfootandgoodswereconveyedbyhorseandcart.Buttheearlyfactoriesbuiltinthe1840‘swerelocatedalongwaterwaysandnearrailheadsattheedgesofcities,andhousingwasneededforthethousandsofpeopledrawnbytheprospectofemployment.Intime,thefactoriesweresurroundedbyproliferatingmilltownsofapartmentsandrowhousesthatabuttedtheolder,maincities.Asadefenseagainstthisencroachmentandtoenlargetheirtaxbases,thecitiesappropriatedtheirindustrialneighbors.In1854,forexample,thecityofPhiladelphiaannexedmostofPhiladelphiaCounty.SimilarmunicipalmaneuverstookplaceinChicagoandinNewYork.Indeed,mostgreatcitiesoftheUnitedStatesachievedsuchstatusonlybyincorporatingthecommunitiesalongtheirborders.Withtheaccelerationofindustrialgrowthcameacuteurbancrowdingandaccompanyingsocialstress-conditionsthatbegantoapproachdisastrousproportionswhen,in1888,thefirstcommerciallysuccessfulelectrictractionlinewasdeveloped.Withinafewyearsthehorse-drawntrolleyswereretiredandelectricstreetcarnetworkscrisscrossedandconnectedeverymajorurbanarea,fosteringawaveofsuburbanizationthattransformedthecompactindustrialcityintoadispersedmetropolis.Thisfirstphaseofmass-scalesuburbanizationwasreinforcedbythesimultaneousemergenceoftheurbanMiddleClass,whosedesiresforhomeownershipinneighborhoodsfarfromtheaginginnercityweresatisfiedbythedevelopersofsingle-familyhousingtracts.