prep 一道SC求解释啊！！！

naryi

After several years of rapid growth, the health 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.

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

B. while it then proved unable to handle the increase in business and fell months behind in its payment to

C. but then it proved unable to handle the increase in business, falling months behind in its paying

D. but then proving unable to handle the increase in business, falling months behind in paying

E. but then proved unable to handle the increase in business, falling months behind in paying

答案是E 不是说逗号分开的句子，虽然有but连接，但也要有独立主谓吗
E是省略了相同的主语

这两种判断方法怎样区分？跟连词有关，还是跟有无逗号有关，还是看是否动作是同一主语？

请NN帮助啊~~谢谢。。

DUKB24

manhattan上面ron的解释：

the comma is sometimes employed when “but” is used to connect units smaller than clauses, if those units are so long that the sentence becomes difficult to read without the comma.

for instance:
James tried to sneak back into the house at 5 a.m. without waking his parents, but climbed through a window directly into the room where his father was already getting dressed.
--> try taking out the comma; if you do, the sentence becomes an unreadable blob.


2）不要去纠结标点的使用
this isn't *normally* the way such things are punctuated, but there are lots and lots and lots and lots of exceptions to punctuation rules.
fortunately, punctuation is NOT tested on the gmat.

basically, you should use punctuation as a guideline for understanding sentences, but you should NOT try to eliminate choices by using "punctuation errors". that is not something that is tested on this exam.

naryi

谢谢啊！很有用！