Can you hear the girls in the next room?A. sangB. tosingC. singingD. sing

问题补充：

Can you hear the girls in the next room?

A. sang

B. tosing

C. singing

D. sing

答案：

A. sang

B. tosing

(答案→)C. singing

D. sing

解析：句意：你能听见这些女孩们正在隔壁房间唱歌吗？ hear sb doing sth 听见某人正在做某事，根据句意，故选C