---Remember the first time we met, Mary?
---Sure．You in the supermarket．
A. had shopped
B. have shopped
C. were shopping
D. shopped
网友回答
A. had shopped
B. have shopped
(答案→)C. were shopping
D. shopped
解析：考查时态。句意：——还记得我们第一次见面的情景吗？——记得，那时候你正在图书馆读书！强调的是当时正在干什么，所以选C 过去进行时态。