we heard betty sing a song just now.betty___ ____ ____ _______a song just now by us

We heard Betty sing a song just now.Betty _______ ______ _____ _______ a song just now by us we heard betty sing a song just now.betty___ ____ ____ _______a song just now by us 英语句型转换,.主动变被动!Q：We heard Betty sing a song just now.Betty ___ ___ ___ ___ a song just now by us. 我认为应该填was heard,不过这道题给了四个空,我不知道该怎么填.请给个答案啊! we heard them sing in shanghai 改为被动语态 we heard her sing at the part last sunday we often hear her sing the song同义句转换 _____ is often heard _____ sing the song. 将下列句子改为被动语态!Who wrote this novel?We heard him sing this song. 改为被动语态：We heard him sing in his room just now we heard a girl sing in the next room just now的被动语态是什么 we often heard her sing in the next room 为什么动词不是ing形式的? we heard her_____ (sing)in the next room a moment ago. we heard her sing in the next room.变成被动语态 We heard Tom sing an English song just now.改为被动 we heard Tom sing an English song just now.是从句么 we heard her sing at the party last sunday变为被动语态 改为被动语态,We ofen heard Mary sing in her bedroom. last sunday we heard them sing peking opra in that theatre改为被动语态 we heard the girl _(sing)at this time yesterday ,中间填?为什么?