一道难题,高人来看看

1.        Developing nations in various parts of the world have amassed $700 billion in debts; at stake, should a significant number of these debts be repudiated, is the solvency of some of the world’s largest multinational banks.

(A) should a significant number of these debts be repudiated, is

(B) should a significant number of these debts be repudiated, are

(C) should they repudiate a significant number of these debts, are

(D) if there is a repudiation of a significant number of these debts, would be（A）

(E) if a significant number of these debts will be repudiated, is

请问为什么选A.  选项E怎么不对.请牛牛指点.

这是个虚拟语气，从句也必须用should，不应该改为will, 表示根本不可能出现的事情。

另外，个人觉得，原句如果采用了某种方式的倒装，正确答案一般是不变的。

if引导的从句中不可能出现将来时

should a significant number of these debts be repudiated, is the solvency of some of the world’s largest multinational banks.

主语是solvency ，BC的are不对了

D的时态不对，主语过去将来时，从句一般现在时

Ewill be没有表达出虚拟的语气。而且if 从句通常用一般现在时，主句用将来时。

for discussion

可大家注意，当if 只有在做“如果或假设”的从句时，将来时态改为一般现在时；

但如果if是表示“是否”的意思时，将来时态还应该是将来时态，这是我们从前学的。这里是做是否的意思，不应变时态。

这是个倒装：at stake, should a significant number of these debts be repudiated, is the solvency of some of the world’s largest multinational banks

实际上是should a significant number of these debts be repudiated，the solvency of some of the world’s largest multinational banks is at stake

should引导的从句是假设的一种特殊形式，相当于：if a significant number of these debts is repudiated