被动语态问句Did Mary sing a chinese song?改为被动语态

被动语态问句Did Mary sing a chinese song?改为被动语态 改为被动语态,We ofen heard Mary sing in her bedroom. 改为被动语态when did you hear her sing this song I gave a book to Mary last week.Do we use them for poeting letters?Where did you build the bredge?Can she finish her homework today?We heard Tom sing an English song just now.改为被动语态 I gave a book to Mary last week.Do we use them for poeting letters?Where did you build the bredge?Can she finish her homework today?We heard Tom sing an English song just now.改为被动语态 she often sing song 变被动语态 改为被动语态2You must take good care of the children3when did you hear her sing this song 改为被动语态：Mary grows beautiful flowers. 把下列句子改为被动语态 I often hear Mary sing English songs at home.2.A policeman is running after a theif in the street. we often sing the song如何变被动语态 把can she sing the song?改为被动语态 i heard lucy sing just now 变被动语态 Is he going to sing a song(改为被动语态) we heard them sing in shanghai 改为被动语态 Mary bought me some books yeasterday.改为被动语态 改为被动语态Mary often takes care of the Children. mary will sweep the floor.变被动语态 The heard Mary laugh just now.怎样改成被动语态