[求助]请教两题gmat prep语法

1、Each year companies in the United
                    State could save as much as $58 billion annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided offices with cleaner air.

A　
                annually by preventing illness among employees and gain as much as $200 billion through improving performance of workers if they simply provided

B　annually if they prevented employee illness and gain as much as $200 billion through worker performance improved by simply providing

C annually in employee illness prevention and gain as much as $200 billion through worker performance improved by simply providing

Ｄ in employee illness prevention and gain as much as $200 billion through improving performance of workers if they simply provided

Ｅ by preventing illness among employees and gain as much as $200 billion through improved worker performance if they simply provided

 请问这题答案是E，我选A，不知E中的improved是过去分词修饰perfoemance吗？为什么用improving 不行呢？

Women are expected to be the majority of student entering law school this fall, a trend ultimately placing more women in leadership position in politics and business.

A Women are expected to be the majority of student entering law school this fall, a trend ultimately placing

B The majority of students entering law school this fall are expected to be women, a trend that will ultimately place

C The majority of students entering law school this fall are expected to be women, which will ultimately place

D It is expected that the majority of students entering law school this fall will be women, a trend ultimately placing

E It is expected for the women to be the majority of students entering law school this fall, which will ultimately place

这题答案是B，我选A，两个选项如何区分呢？

谢谢！！

第一题我支持A

improved worker performance if they simply provided

they的指代有问题。

第二题支持B

A：a trend ultimately placing有问题，分词修饰一个尚未发生的趋势，还是will较好

trend来看，还是B好。

第一题的they在 if的条件状语从句里面，不是优先指代主居主语吗?

A和B中的improving 和improved如何区别呢？

第二题的A和B前半句意思上有什么差别呢？

谢谢!

第一题annually 与every year 重复

第二题women放到前面改变了原文的意思，另外这个trend应该是预测，定语从句用will时态能体现出来。