When will he come is not known哪里出错

When will he come is not known哪里出错 When he will come is not known.为什么用被动语态? when and why he will come has not known.这道题改错、 when he will come is not konwn yet,but when he comes,he will When and why he came here () yet?A is not known B are not kn When he will come back ( )he will come or not is still unknown It is not certain whether he will come. he,whether,not ,is,will,come,uncertain,or When and why he came here ________ yet.A.is not known B.are he who will not learn when he is young will regret it when h ( )he has gone is not known yet.