—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.should it have been
—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.should it have been
C
根据句意，表示对过去的推测，故选could have done。