If we adequate preparations, the conference wouldn’t have been so successful.
A. haven’t made
B. wouldn’t make
C. didn’t make
D. hadn’t made
网友回答
A. haven’t made
B. wouldn’t make
C. didn’t make
(答案→)D. hadn’t made
解析：考查虚拟语气的用法。在虚拟条件句中，表示与过去事实相反的情况，从句用过去完成时，主句用would have done的形式。句意：如果我们没有做好充分的准备，会议就不会这样成功。