求助Prep 两题

7.  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

A: each year 和annually 意思重复，improving 表过程不表结果，应用improved，

B: 同上

C: 同上
            

D: in employee illness prevention要表达的意思错，

E: correct

疑问：此题中，时间为each year，如果准确的讲，是不是从句中的动词时态应是一般现在式呢，为什么答案中是过去式呢？

请指教：）

A. scientists learned how to make a synthetic growth hormone, removing it painstakingly

B. scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly

C. scientist learned how to synthesize the growth hormone, it had to be painstakingly removed

D. learning how to make a synthetic growth hormone, scientists had to remove it painstakingly

E. Learning how to synthesize the growth hormone, it have to be painstakingly removed by scientists

A: make a synthetic不如直接用动词synthesize有效率；后半句不是完整句，主从句关系不成立

B: before加过去完成时没有道理，learn这个动作实际应该在主句动词时间之后

C: correct

D: 从原句逻辑上看，句意中的hormone并不是被同一群科学家使用，而是表述了一种历史事件之后，hormone就可以被后来的所有人怎样怎样了，所以D从逻辑上有问题。

E: learning的逻辑主语不是hormone

注意：

1、             此题很难，要从逻辑上判断意思，以后遇到主动、被动时态的考点，一定要区分清楚施加对象和被施加对象的合理逻辑关系。什么时候用被动？当找不到主动动作发出者时，一定用被动！

2、             还有Before介词+doing，和让步状语从句的省略+doing的区别，When/while（时间）/if/unless（条件）/even though/even if/although（即使）/once＋名词/形容词/完整句

请问注意2中，具体区别是？

请教怎样区分？

7：通过 each year 和 annually 排除 A， B， C，

   by doing  表达原因最清楚， 选 E

  文中用的是 Could save, 所以过去式阿，觉得是虚拟语气

11:  D选项意思有些改变，
            C 更优选

多谢！ 明了多了！