Q19:

After several years of rapid growth, the healthy care company became one of the largest health care providers in the metropolitan area, while it then proved unable to handle the increase in business, falling months behind in its payment to doctors and hospitals.

1. while it then proved unable to handle the increase in business, falling months behind in its payment to
2. while it then proved unable to handle the increase in business and fell months behind in its payment to
3. but then it proved unable to handle the increase in business, falling months behind in its paying
4. but then proving unable to handle the increase in business, falling months behind in paying
5. but then proved unable to handle the increase in business, falling months behind in paying

感觉fall months behind in paying是对前面prove unable to handle the increase in business的解释，所以fell和proved并列做谓语不符合句意，而且it没有必要重复，因为主语是一致的。E总体也符合简洁的原则。

请大牛们也来讲讲吧。

这道题我本来也是错而且也是选的B的，但是我觉得应该从错题中吸收一些经验。我的思路是这样的

首先不论是while还是but在这里后面都应该是跟一个完整的句子，也就是主谓宾应该是全的，所以排除DE.那么先在我们就来看一下ABC的区别，首先A用falling放在句尾表伴随，这个状态我一直认为在GMAT之中就不要改，因为做了很多题，基本上这样的结构可以说在GMAT中是一定对的，我也不敢肯定，但是据我看来就是这样的，B的缺点就是在这里他将本来是伴随结果的一个形式改成了并列形式，所以可以说是改变句子原意，错。C不仅是then还有就是楼上说的in his paying就算这里paying是做动名词，后面也应该有个of 一类的吧！所以也错

Q19:

After several years of rapid growth, the healthy care company became one of the largest health care providers in the metropolitan area, while it then proved unable to handle the increase in business, falling months behind in its payment to doctors and hospitals.

1. while it then proved unable to handle the increase in business, falling months behind in its payment to

2. while it then proved unable to handle the increase in business and fell months behind in its payment to
3. but then it proved unable to handle the increase in business, falling months behind in its paying
4. but then proving unable to handle the increase in business, falling months behind in paying
5. but then proved unable to handle the increase in business, falling months behind in paying

Answer: A