---- Did you visit the Big Ben in London?
---- No, we it, but we spent too much time shopping.
A. could visit
B. could have visited
C. must ahave visited it
D. can have visited
网友回答
A. could visit
(答案→)B. could have visited
C. must ahave visited it
D. can have visited
解析：考查情态动词的用法。依据句意原本能够事实并非如此，用could have done 形式。