--- You can’t have enjoyed your picnic in the rain last Saturday, I’m afraid.
--- On the contrary, we .
A. can
B. must
C. did
D. have
网友回答
A. can
B. must
(答案→)C. did
D. have
解析： 考察代替。句义：—恐怕上星期六，你们在野餐的时候玩得很不好的。—恰恰相反，我们玩得很开心。本句中使用did来代替上文提及的enjoyed your picnic这一在过去所发生的事情。故C正确。