had been done & having been done 区别All the flights____because of the snowstorm,we had to take the train instead.A.were canceled B.had been canceled C.having canceled D.having been canceled为什么不是B,不是应该用过去完成时吗?

what had been done had been done. had been done 怎么用? has been done,had been done 的区别是什么? had been done和 had done有什么区别呢? 英语had done 和had been done区别 had been doing 和had been done有什么差别 had been doing 和had been done有什么差别? had been done 用于什么时态? have done.have been done .had done.had been done 有什么区别?怎么用?有什么结构? 英语时态区分have done .have been doing.had done.had been doing.有什么区别. had been doing 和 had done的区别 is done,was done的被动语态是?is being done,was being done,has been done,had been done,will be done的被动语态是? has been done 与had been done要怎么用啊 had been done与had done是什么结构 他们的用法是什么 请用had been done造几个句子,并翻译 来一位高手辨析一下这个英语区别has done had done has been done had been done 区别是什么如何翻译? My work ___,I went home.A.had been done B.done C.having done D.to be done Much___to fight against pollution.A.have been done B,has been done C,had been done D.has done为什么是选B?