Question

2. When I was walking past his room yesterday evening, I heard him piano.

   A. playing   B. play the   

   C. playing the   D. play

Answer 1

2. C

2. C解析：play与乐器连用时，乐器名词前用定冠词the。hear sb. doing sth.表示“听到某人正在做某事”，hear sb. do sth.表示“经常听到某人做某事”。根据句意“昨天晚上当我走过他的房间时，我听到他正在弹钢琴”，可知选C。