根据下列内容，回答206-210题。 Socialchangeismorelikelytooccurinsocietieswherethereisamixtureofdifferentkindsofpeoplethaninsocietieswherepeoplearesimilarinmanyways.Thesimplereasonforthisisthattherearemoredifferentwaysoflookingatthingspresentinthefirstkindofsociety.Therearemoreideas,moredisagreementsininterest,andmoregroupsandorganizationswithdifferentbeliefs.Inaddition,thereisusuallyagreaterworldlyinterestandgreatertoleranceinmixedsocieties.Allthesefactorstendtopromotesocialchangebyopeningmoreareasoflifetodecision. Inasocietywherepeoplearequitesimilarinmanyways,therearefeweroccasionsforpeopletoseetheneedortheopportunityforchangebecauseeverythingseemstobethesame.Andalthoughconditionsmaynotbesatisfactory,theyareatleastcustomaryandundisputed. Withinasociety,socialchangesisalsolikelytooccurmorefrequentlyandmorereadilyinthematerialaspectsoftheculturethaninthenon-material,forexample,intechnologyratherthaninvalues;inwhathasbeenlearnedlaterinliferatherthanwhatwaslearnedearly;inthelessbasicandlessemotionalaspectsofsocietythanintheiropposites;inthesimpleelementsratherthaninthecomplexones;informratherthaninsubstance;andinelementsthatareacceptabletothecultureratherthaninstrangeelements. Furthermore,socialchangeiseasierifitisgradual.Forexample,itcomesmorereadilyinhumanrelationsonacontinuousscaleratherthanonewithsharpdifference.ThisisonereasonwhychangehasnotcomemorequicklytoBlackAmericansascomparedtootherAmericanminorities,becauseofthesharpdifferenceinappearancebetweenthemandtheirwhitecounterparts. Thepassageismainlydiscussing__________.
A.certain factors that determine the ease with which social changes occur B.certain factors that promote social change C.the necessity of social change D.two different societies正确答案A
