求解决一道英语选择题 While he was ----about in the street,he met an old friend by chance.

问题描述:

求解决一道英语选择题 While he was ----about in the street,he met an old friend by chance.
选项;A.wandering B.wondering C.wondered D.wandered

选A,be doing,进行时,排除C、D.
wander”无目的的闲逛“
wonder"想知道”
排除B