233. Recently implemented “shift-work equations” based on studies of the human sleep cycle have reduced sickness, sleeping on the job, fatigue among shift workers, and have raised production efficiency in various industries.

(A) fatigue among shift workers, and have raised

(B) fatigue among shift workers, and raised

(C) and fatigue among shift workers while raising

(D) lowered fatigue among shift workers, and raised（C）

(E) and fatigue among shift workers was lowered while raising

The best answer, C, grammatically states that the equations... have reduced x, y, and z. and have raised efficiency（大小平行，减少了X，Y and Z,增加了M）. Choices A and B fail to use and to signal that fatigue among shift workers completes the series begun by have reduced, and so produce awkward and unclear sentences. （一层平行的最后一项，一定要用and，不然平行不清且笨拙）Both D and E fail to use and to introduce the last item in the list, which is sleeping in these constructions. In E, while raising has no logical referent, producing only the absurd statement that fatigue has raised efficiency. （？？？？while+doing,中间省略了主语+be动词，一见while要找出逻辑主语，若有两种可能，则歧义）（while从句的主语和主句主语相同，可简化为while引导的分词结构:只要主语相同，并不需要前句的谓语也是be动词）

In E, while raising has no logical referent, producing only the absurd statement that fatigue has raised efficiency.

是否一见while 就需要找它的逻辑主语 E感觉应该理解为有歧义吧

如果这题中E 前面有逗号 while raising 是否就有logical referent

另一题

OG 178

178. In the last few years, the number of convicted criminals given community service sentences, which allow the criminals to remain unconfined while they perform specific jobs benefiting the public, have risen dramatically.

(A) sentences, which allow the criminals to remain unconfined while they perform specific jobs benefiting the public, have

(B) sentences, performing specific jobs that benefit the public while being allowed to remain unconfined, have

(C) sentences, performing specific jobs beneficial to the public while they are allowed to remain unconfined, have

(D) sentences which allow them to remain unconfined in their performing of specific jobs beneficial to the public has（E）

(E) sentences allowing them to remain unconfined while performing specific jobs that benefit the public has

答案是EE) sentences allowing them to remain unconfined while performing specific jobs that benefit the public has

为何不说while 逻辑指代不清

stoneren 班主的解释是

D的错误首先在于in their performing中的performing，虽然performing可以在一些时候作名词，但是，此处，明显是performance作名词更合理；E中，你提到的问题我想可以用逻辑性进行排除，sentences-allow在逻辑上合理，sentences-performing specific jobs显然不合理，perform jobs的主语应该是人。另：逻辑性排除其实很抽象，但是在阅读OG时会遇到很多例子，尤其是定从和分词作定语的句子中，整理一下这些句子并比较，会在这个方面有所收获。

那么据此 OG233的while的逻辑意思来讲 只可能是on studies of the human sleep cycle raising 不可能是fatigue

谢谢

og 233 while 的逻辑主语是“shift-work equations”（句只主语）而不是fatigue。

og178 while 的逻辑主语指代清楚，因为句子主语逻辑上不可是while 的动作发出。

只有当两个名词在逻辑上都可以做逻辑主语时，才会发生指代不清