问题补充:
----Have you seen Mr. Black these days, Jack?
----Yes, I met him when I in the street yesterday.
A. walked
B. was walking
C. have walked
D. is walking
答案:
A. walked
(答案→)B. was walking
C. have walked
D. is walking
解析:在when 引导的时间状语从句中,when引导的从句的动词可以为延续性动词,也可以是短暂性动词,表示主句的动作发生在从句的动作之中,故选B