How long ________ you been at this school?A.haveB.hasC.doD.did
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A解析本例主要考查助动词的用法。初中英语中主要的助动词有be(am, is, are), was, were, being, been; have, has, had; do, does, did; shall, will, would, should. 助动词be可以用来构成进行时和构成被动语态。如：Her mother is cooking in the kitchen. The young trees should be looked after well. 助动词have, has, had与过去分词构成完成时。如：Has he ever been to Canada?助动词do, does, did主要用来构成否定句、疑问句或用以加强语气或表示恳求。shall, will, would, should主要用来构成将来时。如：Lucy doesn't like playing basketball or football. Where does he e from?