关于平行中逗号的用法，很多人讨论没定案

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

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

The best answer, C, grammatically states that the equations... have reduced x, y, and i. and have raised efficiency. 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. 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.
        

问题：

The best answer, C, grammatically states that the equations... have reduced x, y, and i. and have raised efficieny

是不是意味着A选项改为  and  fatigue among shift workers, and have raised

请问have reduced 和  have raised

我查了一下，三个东东并列的时候，最后的AND前是要逗号的，请参考下题

  大全24：A firm that specializes in the analysis of handwriting claims from a one-page writing sample that it can assess more than three hundred personality traits, including enthusiasm, imagination ,    and ambition.

下面贴的这题也是关于逗号和AND的问题 

是这样的：

平行并列结构的中，A,B,and C是非常普遍的机构

你说的下面一个是形容词的并列

【it is a 形容词A，形容词B 名词】这样的结够是成立的，这里的逗号等于and

但有个前提，两个形容词必须修饰同一个名词。

当然上述结构，在两个形容词间加and是可以的。但是ETS习惯不加。

以上是2个的

A词，B词

A词 and B词

A词，B词,and C词（这里的3词的并列，最后的and还是不好省的，即使是形容词的话）