we heard them sing in shanghai 改为被动语态

we heard them sing in shanghai 改为被动语态 last sunday we heard them sing peking opra in that theatre改为被动语态 I heard them sing in the classroom.是对的,为什么I heard them singing in the classroom.不对?正在唱歌不应该用singing吗? 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 Last Sunday we heard them sing Peking Opera in that theater.应改为They were heard to sing Peking OLast Sunday we heard them sing Peking Opera in that theater.应改为They were heard to sing Peking Opera in that theater last Sunday.为什么不可 I often heard () (sing) in the room .Yesterday,Ben and Kitty __________ (be) at home.They __________ (sing) a lot of songs.I heard them _____________ (sing) loudly. People in the city kept their sorroundings _______(protect).They don't allow unknown people _______(invite) to the ball.I found a strange person _______(walk)nearby our shop yesterday.We heard the song _______(sing)next door.We heard them _______ , I heard a song, my old tears came down, Because of this song, together we listened to sing.翻译 we heard her sing at the part last sunday I heard him singing there改被动句是heard singing还是heard to sing i heard lucy sing just now 变被动语态 I heard someone______(sing) just now.横线上填什么? I heard some children __(sing) a song just now . I heard it by SHE ,sing的正确行式填空I heard it by SHE .(sing) I heard him singing改为被动语态which is correct?then I heard him sing? i heard her singing.i heard her sing.有什么不同啊?