She is heard every day in her room.A. singsB. singC. to singD. singing

问题补充：

She is heard every day in her room.

A. sings

B. sing

C. to sing

D. singing

答案：

A. sings

B. sing

(答案→)C. to sing

D. singing

解析：每天都能听到她在她的房间里面唱歌。Hear后接不带to的不定式做宾语补足，但是当变为被动语态时，要把不定式符号to加上，故选C。