本帖最后由 pfullsomer 于 2010-11-15 06:57 编辑
（1）
GWD-23-Q23
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.
A while[/url][CH1]
it then proved unable to handle the increase in business, falling months behind in its payment to
B while[/url][CH2]
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 [url=]its paying[/url][CH3]
D but then [url=]proving unable[/url][CH4]
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
E the best
[CH1]承前转折用but
[CH2]同A [CH3]one’s doing [CH4]but后面接句子
我的问题是： 1.but 和while 用法，区别，什么时候用while？ 2.one's doing一定错吗？为何？ 谢谢牛牛指点 | 
