【C7】A．similarityB．distinctionC．differenceD．mark

【C2】A．separationB．distinctionC．interactionD．characteristic

【C6】A．changeB．mistakeC．differenceD．mark

Many good friends have a lot in _______.A、similarityB、differenceC、commonD、usual

Animals have a natural ________ for survival.A extinctionB distinctionC institutionD in

【C10】A．diversionB．distinctionC．diversityD．similarity

【C9】A．exceptionB．divisionC．differenceD．alteration