还有三道，敲的手疼啊，大家多多指点

1。sound can travel through water for enormous distaces, prevented from dissipating its acoustic energy as a result of boundaries in the ocean created by water layers of different temperature and densities

  prevented from having its acoustic energy dissipated by

  its acoustic energy prevented from dissipating by

  its acoustic energy prevented from being dissipated as a result of

  preventing its acoustic energy from dissipating by

2。marconi’s conception of the radio was as a substitute for the telephone, a tool for private conversation; instead, it is precisely the opposite, a tool for communicating with a large, public audience.

  marconi conceived of the radio as a tool for private conversation that could substitute for the telephone; instead, it has become

  marconi conceived of the radio to be a tool for private conversation, a substitute for the telephone, which has become

  marconi conceived of the radio to be a substitute for the telephone, a tool for private conversation, other than what it is

after several years of rapid growth, the health care company become one of the largest health care providers in the metropo;itan area, while it then proved unable to handle the increase in business, falling months behind in its payment to doctors and hospitals

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

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

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

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

1。sound can travel through water for enormous distaces, prevented from dissipating its acoustic energy as a result of boundaries in the ocean created by water layers of different temperature and densities

  prevented from having its acoustic energy dissipated by

  its acoustic energy prevented from dissipating by (选这个)

  its acoustic energy prevented from being dissipated as a result of

  preventing its acoustic energy from dissipating by(答案给这个）

   我和你选一样，我觉得我对，想看看大家有没有不同意见

2。marconi’s conception of the radio was as a substitute for the telephone, a tool for private conversation; instead, it is precisely the opposite, a tool for communicating with a large, public audience.

  marconi conceived of the radio as a tool for private conversation that could substitute for the telephone; instead, it has become（选这个）

  marconi conceived of the radio to be a tool for private conversation, a substitute for the telephone, which has become

  marconi conceived of the radio to be a substitute for the telephone, a tool for private conversation, other than what it is（答案给的这个）

我选的和你一样，但是答案给的不一样，想看看有没有不同意见

after several years of rapid growth, the health care company become one of the largest health care providers in the metropo;itan area, while it then proved unable to handle the increase in business, falling months behind in its payment to doctors and hospitals

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

  but then it proved unable to handle the increase in business, falling months behind in its paying（选这个）

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

  but then proved unable to handle the increase in business, falling months behind in paying（答案给这个）

   我选的和你不同，我选的是答案给的这个，直觉。但是我想请教but then在这里的用法，为什么不要这个it或者说为什么要这个it？？

   谢谢上面这个NN的帮助

after several years of rapid growth, the health care company become one of the largest health care providers in the metropo;itan area, while it then proved unable to handle the increase in business, falling months behind in its payment to doctors and hospitals

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

  but then it proved unable to handle the increase in business, falling months behind in its paying（选这个）

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

  but then proved unable to handle the increase in business, falling months behind in paying（答案给这个）

想问楼主，原题是become还是became?

本题答案E应该是不对的。

如果选择E，一般只能认为，But后省略了it is.

而prove与unable连用时，相当于以主动形式表示被动意义的系动词。