The police the lost boy everywhere when he suddenly turned up in a supermarket.
A. searched
B. searched for
C. was searching
D. were searching for
网友回答
A. searched
B. searched for
C. was searching
(答案→)D. were searching for
解析：考查时态。根据句意可知是在他突然再现的时候，这个过去的某个时间点上，正在进行，正在发生的事情。所以使用过去进行时。