求助！OG84题

bobochen

84. Recently physicians have determined that stomach ulcers arenot caused by stress, alcohol, or rich foods, buta bacterium that dwells in the mucous lining of the stomach.

(A) not caused by stress, alcohol, or rich foods, but

(B) not caused by stress, alcohol, or rich foods, but are by

(C) caused not by stress, alcohol, or rich foods, but by

(D) caused not by stress, alcohol, and rich foods, but

(E) caused not by stress, alcohol, and rich foods, but are by

正确答案为C
og原版解答节选如下：

A To preserve parallelism,butshould be followed byby.
B There is no reason to repeat the auxiliary verbare.
想问一下,A,B选项中，but 后不用加caused by吗？只加by 就可以了吗？为什么caused可以省略？
希望大神可以给予解答，谢谢！

bobochen

谢谢各位大牛~

WayneCH2012

Recently physicians have determined that stomach ulcers arenot caused by stress, alcohol, or rich foods, buta bacterium that dwells in the mucous lining of the stomach.
就选项B我问下
stomach ulcers are not caused by stress, alcohol, or rich foods,
but
stomach ulcers are not caused by a bacterium that dwells in the mucous lining of the stomach.
这是为什么判断B为错误的理由
以下是C正确答案展开后的样子
stomach ulcers are caused not by stress, alcohol, or rich foods,
but
stomach ulcers are caused not by a bacterium that dwells in the mucous lining of the stomach.
我脑子快烧了，我认为C选项和B选项展开后逻辑上都说不通，请问这是为什么？

winnielxx

not... but...是一种平行并列结构，not后面和but后面应该接相同的结构
比如 【not +V+介词短语，but+V+介词短语】

liuqiangde

这是not....but....的并列结构：caused not by....but by.......,并列比较的主体是by修饰部分，其公用cause