— Do you still remember when we went to Chongqing?
—I can’t remember now but sometime last summer?
A. could it be
B. might it be
C. could it have been
D. might it have been
网友回答
A. could it be
B. might it be
(答案→)C. could it have been
D. might it have been
解析：could have done对过去的动作可能性的判断。