Itisgenerallyagreedthatthefirsttruecitiesappearedabout5,000yearsagointhefood-producingcommunitiesoftheMiddleEast．ThecitiesofSumeria,EgyptandtheIndusValleypossessedanumberofcharacteristicsthatdistinguishedthemastrulyurban．Thecitieswereverymuchlargerandmoredenselypopulatedthananyprevioussettlement,andtheirfunctionwasclearlydifferentiatedfromthatofthesurroundingvillages．Inthecitiestheoldpatternsofkinshiprelationswerereplacedbyacomplexhierarchyofsocialclassesbasedonthespecializationof labor．Moreover,theneedtokeeprecordsledtothedevelopmentofwritingandarithmetic,andtheincreasedsophisticationofurbansocietygaveanewimpetustoartisticexpressionofeverykind． WhenthebasisofcitylifewasestablishedinEuropetheurbantraditionwasdrawnfromtheancientcitiesoftheMiddleEast,viathecivilizationofGreeceandRome．WecantracethreemainphasesinthegrowthoftheWestEuropeancity．Thefirstoftheseisthemedievalphasewhichextendsfromthebeginningofthe1lthcentury A． D．toabout1,500tothebeginningofthe19thcentury．Thethirdisthemodernphaseextendingfromtheearly19thcenturytothepresentday． Everymedievalcitybeganasasmallsettlement,whichgrewuproundageographicalorculturalfocalpoint．Thiswouldbeapermanentstructuresuchasastronghold,acathedraloralargechurch．Indistrictswheretravelandtradewerewellestablished,itmightbeamarket,arivercrossing,oraplacewheretwoormoretraderoutesmet,instudiesofurbangeographytheoldestpartoftownisreferredtoasthenuclearsettlement．TherearemanysmalltownsinEuropewhereitisstillpossibletotracetheoutlineoftheoriginalnuclearsettlement．Itis,ofcourse, muchmoredifficulttodothisinthecaseifalargemoderncitywhichhasgrowntomanytimesitsoriginalsize． Theancientcitieswerecharacterizedbyallthefollowingexcept__________．
A.larger populations
B.different roles
C.different social classes
D.different locations
正确答案是D