Question

英语语法

6. I ____C____ him the answer ________ possible， but I was so busy then.
A. could tell， if it had been
B. must have told， were it
C. should have told， had it been
D. should have told， should it be
这里正确的用C？为什么不是用D吗？难度 the answer ________ possible是从句吗？

Answer 1

这句话是这样的：Had it beeb possible, I should have told him the answer.
前面的是从句，后面的是主句。你题目里只是翻了个个。
从句里因为把连词if给省略了，所以使用部分倒装，把助动词提前了，从句的意思：如果当时有可能的话，与过去相反。所以用了过去完成式。主句由情态动词的过去式加上动词的完成式构成。should have told应该不用解释了。

Answer 2

I should have told him the answer had it been possible.
后半句是省略了的条件状语从句 且倒装
恢复：if it had been possible
因为对过去事实虚拟
所以用过去完成时。

Answer 3

北大青鸟唐城校区：过去完成时。没错。

追问

I ____C____ him the answer ________ possible这句明明是主语呢？为个么会弄出一个从句呢？不是只有从句才用had it been吗？

Answer 4

这是一个与过去事实相反的并且省略了if 的部分倒装的非真实条件句，正常语序是：I should have told him the answer if it had been possible, but I was so busy then.