PREP遇到的困惑 求助各位！谢谢！！

friendann

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 proves unable to handle the increase in business, falling months behind in its payment to doctors and hospitals.
正确答案：,but then proves unable to handle the increase in business ,falling months behind in paying.
我的答案：but then it proved unable to handle the increase in business, falling months behind in paying

but后面不是应该跟完整句子么，为什么正确选项没有it  还有falling months behind in paying怎么理解啊？

not only....but also...的also能不能省略啊？？小生愚钝忘前辈们指点下

friendann

谢谢楼上~~是写错了 不好意思

lovepiao

我自己的拙见：
1.正确答案but后面跟的也是句子，只不过省略了主语。
主语一致都是the health care company ，所以but表平行，became和proved平行。falling months behind in paying为结果状语。（LZ写的正确答案再看下，应该是proved，而不是proves）
2.not only....but also中also不能省