新prep181 求助

181.
                (32807-!-item-!-188;#058&007145)     (GWD-24-38) C

In January 1994 an oil barge ran aground off the coast of San Juan, Puerto Rico, leaking its cargo of 750,000 gallons into the ocean, while causing the pollution of the city's beaches. 

A.     leaking its cargo of 750000 gallons into the ocean, while causing[CH1]  the pollution of

B.     with its cargo of 750000 gallons leaking into the ocean, and it[CH2]  polluted

C.    and its cargo of 750000 gallons leaked into the ocean, polluting

While前加逗号一般有转折的含义，在这里并不合适。不加逗号时while一般是同时的意思，后接进行时，但在这里也不合适（即使去除while前的逗号），因为这样的用法前面不该也是进行时，可以改为and。

是这样吗？我怎么感觉while前即使不加逗号也有表示转折的意思？

有没有哪位大侠给个例子？

对与while我和楼主有相同的困惑 prep320中一句 见到while要小心 却真的不好体会 看才看到MM的贴 我也认真反省了一下 在这说说我理解的在GMAT中经常遇到的while情况吧

第一点.同一个人或事做出的事情 既有at the same time的意味 又有contrast的意味 这个我解释不出来 看题

OG11-134 Recently implemented “shift-work equations”based 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.且看OG11给的解释:Implementing the equations has reduced sickness, sleeping on the job, and fatigue;at the same time, it has increased efficiency.(这里让我觉得很神奇while doing居然可以等同与has done) 然后它又解释说:the phrase "while raising" provides a clear contrast with have reduced.而且这个while raising的动作发出者是主句主语

然而这个题的A B D选项用的and have raised/raised 没有表达出前面have reduced与后面while raising(have increased)这个contrast

我不记得在哪里做过类似的题目 也是以 while doing作为正确答案的 想必道理是一样的

当然在这里你也可以理解成状语从句的省略 XDF这样说过:只有(even) though, although, if ,unless, when ,while等词引导的从句才可以省略 省略的条件是:a.从句必须是S+be就是主语+be动词 b.从句主语等于被修饰句主语 c.S+be一起省略

第二点.就是所谓的 逗号+while 对比 Longman上这样说的 used to emphasize the difference between two situations, activities etc
Schools in the north tend to be better equipped, while those in the south are relatively poor.

第三点.就是although的意思 表示让步 Longman上说 4
in spite of the fact that
ￚsynonym althoughWhile never a big eater, he did snack a lot.While there was no conclusive evidence, most people thought he was guilty.

这个在楼主MM问的新prep2-223中 AlienX斑斑给出了but与while的最佳解释 也是因为这个解释 我认定while不是转折而是让步 but才是名正言顺的转折 这么说可能比较别扭 但是只要看了AlienX斑斑给出的这个链接就全明白了http://englishforacademicpurposes.blogspot.com/2008/02/although-versus-but.html

然后我们来说这个题:

181.
            (32807-!-item-!-188;#058&007145)     (GWD-24-38)

In January 1994 an oil barge ran aground off the coast of San Juan, Puerto Rico, leaking its cargo of 750,000 gallons into the ocean, while causing the pollution of the city's beaches. 

A. leaking its cargo of 750,000 gallons into the ocean, while causing the pollution of 它这里用了while doing 那就去第一点中找 while doing的逻辑主语是"leaking its cargo of ...gallons into the ocean"与主句主语"an oil barge"根本不一致 况且这里的causing这个动作就算是at the same time发生 也不是a clear contrast

A中的其他错误causing the pollution不如直接polluting&做结果状语表达有效

D. while it leaked its cargo of 750,000 gallons into the ocean and caused the pollution of 也算是逗号+while了 那就去第二点和第三点中找 这里既不能表示 differences in two situations 也不能表示although/despite the fact that/in spite of the fact that

所以prep320中一句见到while要小心 要体会明白真的不容易 毕竟while用对了是最佳选项 用错了是迷惑选项

以上拙见 还望斑斑和NN多多指正