Question

【题目】（题文）（2017 上海市黄浦区九年级4月学业模拟考试）Listen! Someone __________ at the door. Please go and answer it.

A. knocks B. is knocking C. has knocked D. was knocking

Answer 1

【答案】B

【解析】句意：听！有人在敲门。请去看一看。像Listen，look，now等表示现在时间，要用现在进行时态，现在进行时的构成：be+doing；根据Listen!可知现在的时间，要用现在进行时态，结合句意和语境可知选B。