求助~~prep07-1-82 对于ving ved的不解

wenniooooo

82.        (28967-!-item-!-188;#058&003792)

Each year companies in the United States 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

正解：E
A项中的improving和E的improved相比较，为什么解释说improving表示动作的过程,而这里的逻辑意思应该是performance已经被提高,其结果造成了$200billion的收益。所以要用improved，但是要表达improve已经完成了呢，平行位置的preventing不也是ving的形式么，难道我没有理解句意么？
求助。。。求助。。。

wenniooooo

顶。。。。。

soulwangh

The core parts of the parallelism are save and gain.
In parallelism the only thing we should warrant is these two words should parallel with each other.

We don't necessarily make other parts parallel. If we did, we would be writing a poem.

As for E, the vital error is annually and each year. Redundancy.  
IMO,both through improving and through improved performance are Correct.

wenniooooo

soulwangh 发表于 2013-11-23 00:13
The core parts of the parallelism are save and gain.
In parallelism the only thing we should warrant ...

yes! I agree with you , “through improving performance of workers ”and“through improved worker performance” both express the same meaning.

The analysis of prep-07 supposes that these two phrases have different emphasises, but I don't realize that either of these two emphasises is sole expression in this sentence.The sentence do not need a particular emphasis of expression. Both are OK.

soulwangh

wenniooooo 发表于 2013-11-24 18:27
yes! I agree with you , “through improving performance of workers ”and“through improved worker  ...

My experience is if you want to find out the meaning issues, see the native-speaker's opinions.

Sometimes, non-native speakers' explanations are far fetched.  

wenniooooo

I got it ! thanks!

In this period of preparation for GMAT, I realized that a properiate tempo and accuracy usually depend on whether you can find maybe just one serious mistake. For the most time ,we can catch it by the first glimpse of the sentence. Thus, maybe I should not be so serious on some some method of expression that did not change the main meaning of the sentence.

wenniooooo

soulwangh 发表于 2013-11-25 12:08
My experience is if you want to find out the meaning issues, see the native-speaker's opinions.

S ...

I got it ! thanks!

In this period of preparation for GMAT, I realized that a properiate tempo and accuracy usually depend on whether you can find maybe just one serious mistake. For the most time ,we can catch it by the first glimpse of the sentence. Thus, maybe I should not be so serious on some some method of expression that did not change the main meaning of the sentence.