自己总结了特别纠结的while的用法

lizzykin

While的用法
1、意为“当...时”放句首或句中
Prep:
While studying the genetic makeup of corn, Barbara McClintock discovered a new class of mutant genes, a discovery that led to greater understanding of cell differentiation.
这里while引导状语从句省略主谓，说明while可以表示在....时

2、意为“虽然、尽管”让步时，多放在句首。(=although)
OG正确句子：
While all states face similar industrial waste problems, the predominant industries and the regulatory environment of each state obviously determine the types and amounts of waste produced, as well as the cost of disposal.
OG的解释：
The sentence begins with the conjunction while, here used to mean although, and contrasts the similar situation of all states with the varying conditions of each state.
说明GMAT认为while可以在句首表示让步和转折，同样具有对比的意味，对比了所有州相似的情况和每个州不同的情形。
OG正确句子：
While the cost of running nuclear plants is about the same as for other types of power plants, the fixed costs that stem from building nuclear plants make the electricity they generate more expensive.
OG解释：This answer choice clearly and succinctly compares the two types of costs.
同样说明while可以在句首表示让步和转折，语意上有对比

3、在句中表示对比（contrast），这时要注意应该有同时发生的意思，如果并没有同时发生的含义则不用while
OG：
Dressed as a man and using the name Robert Shurtleff, Deborah Sampson, the first woman to draw a soldier’s pension, joined the Continental Army in 1782 at the age of 22, was injured three times, and was discharged in 1783 because she had become too ill to serve.
(A) 22, was injured three times, and was discharged in 1783 because she had become
错误答案B:
(B) 22, was injured three times, while being discharged in 1783 because she had become
OG的解释:While being … indicates that Sampson was injured at the same time she was discharged from the Army.
说明GMAT认为while可在句中表示at the same time的意思，表示同时发生的两件事

OG：
Over 75 percent of the energy produced in France derives from nuclear power, while in
Germany it is just over 33 percent.
OG解释错误的原因：While is somewhat ambiguous, since it might indicate simultaneity rather than contrast
正确答案：whereas nuclear power accounts for just over 33 percent of the energy produced in Germany
说明GMAT认为while出现在句中的时候可能会产生歧义
RON对这道题不用while的解释：
If "while" comes before a complete sentence, then, ideally, it should imply BOTH simultaneity AND contrast.
While HOV (high-occupancy vehicle) lanes do serve the laudable purpose of encouraging carpooling, they also reduce the number of lanes available to solo drivers, increasing both congestion and air pollution.
If "while" comes before a modifier, it serves only to indicate simultaneity.
You shouldn't send text messages while driving.
我自己的理解：因为while表示对比应该有同时发生的意思，但是这句话明显应该想说的只是两个国家的对比，不存在同时发生的意思，所以不用while比较好

OG正确句子：
Recently implemented “shift-work equations” base on studies of the human sleep cycle have reduced sickness, sleeping on the job, and fatigue among shift workers while raising production efficiency in various industries.
OG对这个句子的解释：Implementing the equations has reduced sickness, sleeping on the job, and fatigue; at the same time, it has increased efficiency.在减少...的同时增加...
OG对正确选项的解读：the phrase while raising provides a clear contrast with have reduced.说明while在这里很好的对比了增加和减少（同时+对比)

Prep错误选项:
After several years of rapid growth, the health 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.
Prep的解释：
即便表示转折对比，while也有”at the same time“的含义在里面，与then矛盾
说明在句中，如果要表达转折但是没有同时发生的意思时，不能用while

lizzykin

第三点也是我自己摸索的...要是有什么不对的大家拼命指出！！ 一上午都在看while，看晕了....

无感骚年的逆袭

谢谢啊～ 很棒！

田咯咯哒biu

Mark一下！               

TYHx会好运

感谢分享！               

babyangelasky

Thx for  sharing You lighten me up

Hiiragihane

一个疑问，Ron说while在modifier前只表示同时，那么SC134题C选项的while raising官方给出是provides a clear contrast with have reduced.如何解释？

pheobe-J

谢谢楼主，好详细

Hailee

看一下！               

VC1995

mark.很棒的总结