请教GWD31-4-Q19，多谢！

SGDinosaur

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

答案选E，不太明白为什么，因为连词后面的be动词可以省掉?请顺便帮忙提取一下此句的主谓宾，谢谢！

[此贴子已经被作者于2009/8/5 21:39:49编辑过]

sherry_xiem

A,B选项是因为while 与then 有时间上的语序冲突，C选项中的it指代不清，是the healthy care company 还是虚拟主语,最后，这是个过去时态，是已经完成的动作，而不是正在proving.故我个人选E

SGDinosaur

多谢lsmm,while和then冲突，恩~居然没发现这一点，有收获，请问第二个句子的完整意思是否是 the healthy care company was proved...主语仍然是the healthy care company吗？