PREP 逻辑题，题目看不懂，请NN指点一下

The recent decline in the value of the dollar was triggered by a prediction of slower economic growth in the coming year.
                    But that prediction would not have adversely affected the dollar had it not been for the government’s huge budge deficit, which must therefore be decreased to prevent future currency declines.

Which of the following, if true, would most seriously weaken the conclusion about how to prevent future currency declines?

A. The government has made little attempt to reduce the budget deficit.

B. The budget deficit has not caused a slowdown in economic growth.

C. The value of the dollar declined several times in the year prior to the recent prediction of slower economic growth.

D. Before there was a large budget deficit, predictions of slower economic growth frequently caused declines in the dollar’s value.

e. When there is a large budget deficit, other events in addition to predictions of slower economic growth sometimes trigger declines in currency value.

答案：D

自己顶一下，虚拟条件句？不好理解啊！还是等NN来分析一下。

近日的美元跌势是由于（分析师）对明年（美国）经济增长预测（唱衰）的结果。但是如果政府没有巨大的财政赤字的话，（分析师）的预测是不会对美元产生负面影响的，所以，（政府）应当降低（赤字）以防止美元贬值。

哪个削弱？

a.政府没有设法降低赤字。
b.财政赤字不是造成经济增长放缓的原因。
c.在最近的预测放出之前，美元就已经数次贬值。
d. （政府）还没有财政赤字之前，对于经济增长唱衰的预测就已经数次造成美元贬值。
e.其他因素影响美元币值。

　　谢谢各位NN的解答。偶语法特差，对句子结构不明白。现在从网上找了点资料，来说明本题中出现的语法现象：本句后半句应为虚拟倒装条件句。

部分资料：虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略，再把were, should或had 移到从句句首，实行倒装。

　 Were they here now, they could help us.

　=If they were here now, they could help us.

　 Had you come earlier, you would have met him

　=If you had come earlier, you would have met him.　

　 Should it rain, the crops would be saved.

　=Were it to rain, the crops would be saved.

下面找了2个不错的例句，如有XDJM们对此类结构不清楚，可看看：

1. For example, they do not compensate for gross social inequality, and thus do not tell how able an underprivileged youngster might have been had he grown up under more favorable circumstances.

    要点
        句中had he grown up ... 是虚拟条件中省略if的倒装结构。翻译时,要把if的含义译出。主句为并列谓语"... compensate ... , and ... tell"结构。句中how引导宾语从句。虚拟条件句为宾语从句的状语。
        

译文
        例如,它们并不弥补明显的社会不公；
        因此,它们说明不了一个物质条件差的年轻人,如果在较好的环境下成长,会有多大的才干。
        

2．Low levels of straying are crucial, since the process provides a source of novel genes and a mechanism by which a location can be repopulated should the fish there disappear.（GWD1中第1篇阅读中选摘）

意思是說

因為文章一開始就說是prediction造成dollar value的decline

這一句就是反駁說如果不是因為政府的超額預算赤字

這個prediction也不會對dollar value有負面的影響