求助一道简单语法题（见笑了）

mikiluang

最近对状语的这个语法比较模糊，请教各位这道题目（见笑了..)

Recently implemented "shift-worker equations" based on studies of the human sleep cycle have reduced sickness, sleeping in the job, fatigue among shift workers, and have raised production efficiency in various industies.
A
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

不太明白while为什么不用对称也可以呢?

ranshuyang

答案是什么呢？

mikiluang

答案是C的//

silent7706

这样看这个句子'"shift-worker equations" have reduced sickness[phrase2 +, and phrase 3] while raising production efficiency in various industries.'
对称的是插入的几个phrases，而不是"while"

sportmann

这是我的一点思路，供你参考。

找句子主干。
Equations have reduced sickness, sleeping in the job, 这里最后一个并列词前面加and, 后面再跟一个并列动词或从句。

Equations have reduced A, B, and C, while raising...

首先排除A,B,D因为fatigue前没有and， E虽然有and但是能看出其实前后是两个句子并列，改变了原句的意思。