问题补充：
I would have met him to the cinema last night.
A. have I been
B. had I been
C. if I am
D. if I have been
答案：
A. have I been
(答案→)B. had I been
C. if I am
D. if I have been
解析：考察虚拟语气，根据句子结构可知，该句为if引导的虚拟条件句的省略句，根据I would have met him可知，该句是对过去的虚拟，从句要选择If I had been to ...,省略if 提前had 即为B.
