英语四级考试能力提升训练题及答案2017英语四级考试能力提升训练题及答案Whenthenightisdarkest,dawnisnearest.以下是小编为大家搜索整理的2017英语四级考试能力提升训练题及答案，希望能给大家带来帮助!更多精彩内容请及时关注我们应届毕业生考试网!MasstransportationrevisedthesocialandeconomicfabricoftheAmericancityinthreefundamentalways.Itcatalyzedphysicalexpansion,itsortedoutpeopleandlanduses,anditacceleratedtheinherentinstabilityofurbanlife.Byopeningvastareasofunoccupiedlandforresidentialexpansion,theomnibuses,horserailways,commutertrains,andelectrictrolleyspulledsettledregionsoutwardtwotofourtimesmoredistantformcitycentersthantheywereinthepremodernera.In1850,forexample,thebordersofBostonlayscarcelytwomilesfromtheoldbusinessdistrict;bytheturnofthecenturytheradiusextendedtenmiles.Nowthosewhocouldafforditcouldlivefarremovedfromtheoldcitycenterandstillcommutethereforwork,shopping,andentertainment.Thenewaccessibilityoflandaroundtheperipheryofalmosteverymajorcitysparkedanexplosionofrealestatedevelopmentandfueledwhatwenowknowasurbansprawl.Between1890and1920,forexample,some250,000newresidentiallotswererecordedwithinthebordersofChicago,mostofthemlocatedinoutlyingareas.Overthesameperiod,another550,000wereplottedoutsidethecitylimitsbutwithinthemetropolitanarea.Anxioustotakeadvantageofthepossibilitiesofcommuting,realestatedevelopersadded800,000potentialbuildingsitestotheChicagoregioninjustthirtyyears–lotsthatcouldhavehousedfivetosixmillionpeople.Ofcourse,manywereneveroccupied;therewasalwaysahugesurplusofsubdivided,butvacant,landaroundChicagoandothercities.Theseexcessesunderscoreafeatureofresidentialexpansionrelatedtothegrowthofmasstransportation:urbansprawlwasessentiallyunplanned.Itwascarriedoutbythousandsofsmallinvestorswhopaidlittleheedtocoordinatedlanduseortofuturelandusers.Thosewhopurchasedandpreparedlandforresidentialpurposes,particularlylandnearoroutsidecityborderswheretransitlinesandmiddle-classinhabitantswereanticipated,didsotocreatedemandasmuchastorespondtoit.Chicagoisaprimeexampleofthisprocess.Realestatesubdivisionthereproceededmuchfasterthanpopulationgrowth.1.Withwhich