问题标题:
Inthe1950sintheUSA,mostfamilieshadjustonephoneathome,andwirelessphones_______yet.()A.haven'tinventedB.haven'tbeeninventedC.hadn'tinventedD.hadn'tbeeninvented
问题描述:

Inthe1950sintheUSA,mostfamilieshadjustonephoneathome,andwirelessphones_______yet.()

A.haven'tinvented

B.haven'tbeeninvented

C.hadn'tinvented

D.hadn'tbeeninvented

秦绪文回答:
  答案:D   句中invent与主语phones构成动宾关系,要用被动语态;invent的动作发生在谓语动词had之前,是过去的过去,要用过去完成时态的被动语态.故选D.
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