问题补充：
I would have gone to visit him in the hospital，had it been at all possible，but I fully occupied the whole of last week.
A. were
B. had been
C. have been
D. was
答案：
A. were
B. had been
C. have been
(答案→)D. was
解析：本道题目的前半句话是对过去情况的一种假设，但事实上并没有发生，而事实上没有发生的真实原因是句子的后半部分由but引导的转折句所表述的真实。因而but所引导的句子中应该用表示与过去事实相符合的表陈述的时态，即一般过去时。
