问题
选择题
（河北唐山一中09高三调研，11）— 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
答案
答案：C
could have done对过去的动作可能性的判断。