改为被动语态,We ofen heard Mary sing in her bedroom.

题目

改为被动语态,We ofen heard Mary sing in her bedroom.

答案

Mary is often heard to sing in her bedroom.
在主动语态中,使让动词(make,have,let)和感官动词(see,look,watch,notice,listen,hear,feel,find)后必省略to,但在被动语态中必须加上to