I saw him dancing.改为被动语态

I saw him dancing.改为被动语态 His mother saw him play computer games.(改为被动语态) l saw him go out 改为被动语态 we saw him walk into the classroom 改为被动语态 I heard him singing改为被动语态 改为被动语态：I saw him go into the classrom.2did he buy you the bo I saw him singing in the room.改为被动句 I heard him sing in the classroom改为被动语态? We saw him go into the shop yesterday afternoon.改为被动语态.He wa Someone saw him swam in the lake yesterday.改为被动语态He__ __ __s 改为被动语态1、I saw him walk into the next room.New cars—— —— —— b I saw him playing the piano变成被动语态怎么变