—Did you see Mr. Black just now?—Yes. He his car when I met him.A. parked B. was parkingC

问题补充：

—Did you see Mr. Black just now?

—Yes. He his car when I met him.

A. parked

B. was parking

C. parks

D. will park

答案：

A. parked

(答案→)B. was parking

C. parks

D. will park

解析： 过去进行时表示过去某个时间段正在发生的事情,根据时间状语从句当我遇到他时,可知主句应为过去进行时,选B.