一空一词They have been taking for the whole three hours 改一般疑问句____ they____ ____ for the whole three hours.To spit in public places is not polite.____ isn't polite _____ spit in public places.

(They must have been there yesterday ,______they?)能用weren't they 还是didn't they? Where have they been? I think they were Canadian.I don't think they were.They can't have been Canadian.They must have been Australian.帮我看看有无语法错误 They have a____ been there They must have been here the day before yesterday,__________?A.mustn't they B.didn't they C.mustn't have they D.had they 为什么有yesterday 就要用didn't they?A.为什么不可以呢? 一道英语选择,These trees must have been planted three years ago,____?A weren't they B must't theyC didn't they D haven't they the clothes must have been washed by her just now,___A.didn't they B.hadn't they C.haven't they Not only his parents but also his brother___to the Summer Palace.They haven't been back.A.have been B.have gone C.has gone D.has been They can't have been doing their homework请问can't have been是对刚才所发生的事的推测吗? the greens____the great wall for a vacation.they aren't at home now用have been in/have been to/have gone to填空 They must have been enjoying themselves there,or they _____ so long.[A] can't have stayed [B]wouldn't have stayed [C] needn't have stayed [D] couldn't stay为什么选B?清翻译整句 Greens must have been to Shanghai ,_____they?A.hadn't B.didn't C.can't D.weren't还有haven‘t they have/has been doing否定形式是“They don't have been seeing each other these days.”是“They haven't been seeing each other these days.”Have you been learning English for ten years?是 No,I have't.还是 No,I don't.是 It is necessary of us They can’t have been doing their homework ---doing是什么词性?have been 在这里还是表现在完成时吗 what have they been doing 是什么时态 What places have they been?怎么翻译? where have they been?是现在完成时吗? they have been in kate's for