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:句意:这些天你有看见布莱克先生吗,杰克?是的,当我昨天正在街道上走着时,遇到他了。用过去进行时表示动作正在进行,故选B