问题
选择题
While Helen _____ along the river after supper, she ____ a wallet lying on the roadside.
A. was walking; was finding B. walked; found
B. walked; was finding D. was walking; found
答案
答案：D
题目分析：While引导的从句表示两个动作同时进行或紧接着发生，find为短暂性动作，通常不用进行时，句意为：晚饭后海伦沿着河边散步的时候，发现路边有个钱包。故选D。