Did he have a key?这里的he是第三人称,为什么不用has而用have?

Did he have a key?这里的he是第三人称,为什么不用has而用have? -----you----the key Yes,it was in my bag .A.Have ,found B.Did ,find Not only did he give me a book 这里为什么用did he I don't think he could have done such a stupid thing last night,__ A.could he B had he Cdid he这里could不是情态动词,have不是助动词吗?为什么要用did?（答案选C） He can't find his key.He ---------- them.A.must lost B.must have been lost C.must have lost Did he have a good time?同意句Did he[2格] yesterday 为什么Does he have a tennis ball?这里用have? He spent as much time playing as he___.A.studyingB.was studyingC.studiedD.did studyingwhy?key上是Dwhy？ Did he have a good time last sunday?同义句 He did not have confidence____himself.A.onB.inC.withD.about Not until then （ ）that he was wrong.A he realized B he did realize C did he realize D had he realized这里的各个选项详解 What a pity!Considering his ability and experience,he(?)better.The key ismight have done.Why n...What a pity!Considering his ability and experience,he(?)better.The key ismight have done.Why notcan have done? What a pity!Considering his ability and experience,he(?)better.The key ismight have done.Why n...What a pity!Considering his ability and experience,he(?)better.The key ismight have done.Why notcan have done? 还有I have a set of (key). 改错 I have a set of key. He did not have a good reputation in his home town.这里为什么用have而不用had?过去式的话应该是要用had啊.那had应该在什么情况下使用? ---Did he have a good time at the party?---Yes.He enjoyed h_________. He did not have ( ) money for a taxi ,( ) he walked back to the hotel