(2013·高考湖南卷)—I don’t understand why you didn’t go to the lecture yesterday afternoon.
—I’m so sorry.But I my homework.
A. had done
B. was doing
C. would do
D. am doing
网友回答
A. had done
(答案→)B. was doing
C. would do
D. am doing
解析：选B。题干的意思是：“我无法理解你昨天下午为什么没去听讲座。”“对不起，但是那时我正在做作业。”根据语境可知“做作业”是昨天下午举行讲座的那段时间内正在发生的动作，故用过去进行时，由此可知答案为B。