问题补充：
If we the tickets half a year ago, we would not be able to visit it on May Day now.
A. did not book
B. had not booked [来源:]
C. would not book
D. would not have booked
答案：
A. did not book
(答案→)B. had not booked [来源:]
C. would not book
D. would not have booked
解析：可联系答.案.网客服索取。
