Yesterday evening I heard my teacher __ in the next room.A.sang B_英语解答

Yesterday evening I heard my teacher __ in the next room.
A.sang B.to sing C.singing D.to be singing
Why？

人气：255 ℃　时间：2019-12-09 10:11:56

解答

C
hear的用法有两种：hear sb.do or doing sth.
听到老师在隔壁教室说话是指那个时候听到而不是一直在那听所以用ing形式的