We heard Kitty sing in the next room this morning.改为被动语态

问题描述:

We heard Kitty sing in the next room this morning.改为被动语态
Kitty _______ _______ ________sing in the next room this morning.

was heard to;
主动语态:hear sb do sth;
被动语态:sb be heard to do sth:一定要加上to;