Question

____,george would have been a rich man.

A.If he were to enter business
B.if he was to enter business
C.was he to enter business
D.Had he entered business.
答案是D。不过我想知道为什么？

Answer 1

当虚拟条件句的谓语动词含有were, should, had时，if可以省略，这时条件从句要用倒装语序，即把were, should, had等词置于句首，这种多用于书面语。
例如：
Should he agree to go there, we would send him there.
(Should he = If he should) 要是他答应去的话，我们就派他去。
Were she here, she would agree with us.
(Were she = If she were) 如果她在这儿的话，她会同意我们的。
本题：
Had he entered business, George would have been a rich man.
(Had he = If he had) 如果他去经商的话，乔治应该已经是个富人啦。

想知道更多关于虚拟语气应用上的变化，可参考下列百度百科的材料。

Answer 2

____,george would have been a rich man
A.If he were to enter business
B.if he was to enter business
C.was he to enter business
D.Had he entered business.
选D
这是一句省略了if的虚拟语气
省略了之后句子要倒装，助动词放第一个
ABC的时态都不正确
有不会的可以再问我.