改为被动语态My mother looks after my little brother和We heard her sing the next room
问题描述：
改为被动语态My mother looks after my little brother和We heard her sing the next room
答
1.my little brother is looked after by My mother .
2.she was heard to sing in the next room.
答
My little brother is looked after by my mother.
She was heard sing in the next room.