I heard her in her room when I passed by. Ato sing

题目

I heard her in her room when I passed by. Ato sing
I heard her in her room when I passed by.
Ato sing
Bsinging
Csing
Dsings

答案

Bsinging
hear sb doing 听到某人正在做.
hear sb do 听到某人做过某事,如.I heard him come from Canada.我听说他来自加拿大.
根据前后句的意思：当我经过时,我听到她正在房间里唱歌.