6、的动作,但现在完成时强调这一动作与现在有关,表示对现在产生的影响或结果;而一般过去时只表示动作发生在过去,跟现在没有关系。如:Ihavealreadycleaned(clean)ourclassroom.我已经打扫了教室。Icleaned(clean)ourclassroomjustnow.刚才我打扫了教室。句子中如有yesterday,last,justnow,in1999等过去时间词就只用一般过去时。特别提醒:句子中如有特殊疑问词when出现,一定不能用完成时。( B )①—Thesefarme
7、rshavebeentotheUnitedStates.—Really?When________there?A.willtheygo B.didtheygo C.dotheygo D.havetheygo( B )②—________you________yourhomeworkyet?—Yes,I________itamomentago.A.Did;do;finishedB.Have;done;finishedC.Have;done;havefinishedD.will;do;finishTask