They have known him_to have been arrested___(arrest) by

来源：学生作业帮编辑：灵鹊做题网作业帮分类：英语作业时间：2024/05/05 20:19:17

They have known him___to have been arrested_____(arrest) by the police.划线上为什么用不定式的被动语态啊,应该没有know sb to
还有为什么是不定式被动语态的完成时啊，主要是两点：1.为什么是用不定式 2.为什么是完成时态

动词不定式是属于非谓语动词你要考虑非谓动词和其主语的关系他的主语是him 而不是they him 和 arrest之间是被动关系所以用被动语态即动词不定式的被动语态.
至于为什么是完成时态你要看 arrest 和know之间的时间顺序肯定是先arrest 才know 对吧 know已经用了完成时态 arrest 肯定是过去完成时可是动词不定式不能写成 to had done 结构只能用to have done 来代替又因为是被动语态所以是 to have been done

They have known him___to have been arrested_____(arrest) by --- Have clothes been washed yet?---Yes,they _____ (wash)by They will have been married for 20 years by then. Where have they been? It s____ that they have known it I suppose they have known about it ,( known,how long,have they,each other 英语?They will have been married for 20 years by then.请问been在句 They will have been married for 20 years by then.这里的been 表示什 What places have they been? They have a____ been there they have been put to shame by a boy.they should feel___