whEn thE Author sAys thAt "CErEn's ArChitECturE, CrAFts, AnD AgriCulturE wErE surprisingly sophistiCAtED AnD vAriED.", hE mEAns_____.
A．CErEn At thAt timE EnjoyED A high CivilizAtion
B．pEoplE in CErEn wErE morE intElligEnt thAn pEoplE toDAy
C．CErEn's DisAppEArAnCE wAs A trAgEDy
D．thE powEr oF nAturE wAs grEAt