[求助]关于so as to 用法

我在网上查到so as to有两种形式的用法：

一、so ... as to表示如此……以至于，省略号用形容词或副词代替

二、so as to=in order to 表示以便于

但是OG黄皮那本里这两道题的解释让我对so as to的用法产生疑惑。

33. Although schistosomiasis is not often fatal, it is so debilitating that it has become an economic drain on many developing countries.
(A) it is so debilitating that it has become an economic
(B) it is of such debilitation, it has become an economical
(C) so debilitating is it as to become an economic
(D) such is its debilitation, it becomes an economical
(E) there is so much debilitation that it has become an economical

我也能理解最佳答案肯定是A，但是对于C，书中给出的解释是The construction so x as to y is not a correct idiom。而我查到的情况so x as to y应该是存在的用法啊，本例中 so debilitating is it as to become an economic能否看作是it is so debilitating as to become an economic的倒装呢？如果是倒装，好像也没什么大的错误啊？

类似的还有

36. In 1527 King Henry VIII sought to have his marriage to Queen Catherine annulled so as to marry Anne Boleyn.
(A) so as to marry
(B) and so could be married to
(C) to be married to
(D) so that he could marry
(E) in order that he would marry

也排除了A答案，理由同样是So as to marry is not idiomatically correct; it does not identify who will marry。但是明明可以找到很多so as to表目的的用法，比如He got up earlier so as to get to school on time.

请各位帮忙对so as to的用法发表一下意见吧。

Thx a lot!

那个，OG说的话就是GMAT的规则，咱在人家这里考试，就得遵守人家的规则。

so as to是GAMT非常不喜欢的一种用法，因为这个用法容易造成歧义。一般情况下，只有在系表结构里才使用。

我刚刚也正被这个问题缠着，现在说说我的看法。

第一：so as to 等于 in order to 表目的或表结果。一般用于句中，但较in oder to 比较口语化，所以我认为这个应给类似与maybe 是一个比错标志。

第二：so....as to(之前我还提了关于这个的一个问题）是正确的用法，如此。。。以至于。。他可以是正确答案。可以去看我问的那个问题http://forum.chasedream.com/dispbbs.asp?boardID=23&ID=367421&page=1

而你所的第一题为什么不选，第一是因为倒装，倒装是表示语气强调的，这种形式原文有，必须保留而原文不是，也不应改成倒装。另外

so debilitating is it as to become an economic中的so debilitating is it as to 也不符合so...as to 的要求 因为中间有个 it is.当然要倒装只能这样倒，不过也说不过去啊。

至于你说的第二题so as to marry Anne Boleyn.就如我之前所说，过于口语化。