when and why he came here _____not known yet .为什么填is?（is为标准答

When and why he came here () yet?A is not known B are not kn When and why he came here ________ yet.A.is not known B.are when and why he came here _____ yet. When and why he came here ________ yet.选什么 When and why he came here ___ yet 为什么横线上的谓语动词用单数 请英语帝,讲解这道题when and why he came here _______yet.a\is not know ( )he has gone is not known yet. 英语语法I suppose that is why he came to me when he went broke,t leaving you out here is that why i came here Is Peter here yet?Not yet,but he( ) be here soon.He is usual --Is Tom here yet? 这个句子为什么是助于从句啊.where he has gone is not known yet.where 为什么是主