旧PREP 74题 有关but的用法

dengyichao

Paleontologist Stephen Jay Gould has argued that many biological traits are not the products of natural selection, favored due to their enhancement of reproduction or survival, but that they are simply random by-products of other evolutionary developments.

(A) due to their enhancement of reproduction or survival, but that they are

(B) due to the reproduction or survival they enhance, but they are

(C) because they enhance reproduction or survival, but

(D) because they enhance reproduction or survival, but are

(E) because of enhancing reprouction or survival, but are
选D可理解为but连接两个位于many biological traits are not...but are....
可是C也可以理解为not...but...结构，并列了the products of natural selection和simply random by-products of other evolutionary developments，为什么C不对呢？

dengyichao

upup

逆时桢

upup

洛洛洛洛

求解...

yiwuxie15

顶起，求牛人解答

steinlala

我的理解是，不能单纯的看并列，还要理解句意，because they enhance reproduction or survival, but （they省略）are simply random by....作者要说明的是，前句表示动作，后句是个simply random，是个事件，两者性质不同，因此are不能省略。

米样

是有这样的一些说法的，比如
在某些情况下,并列结构的第二个成分的谓语动词可以省略:两个句子并列,第一个句子含有be动词或者become,第二个句子中的be动词或者become必须省略,同时,一些重复的名词或形容词也必须省略.
但是，并不是绝对的！句子的简洁、清晰、有效，才是GMAT语法的王道。

大家碰到BUT要小心了！
因为其作为介词，有“除了”的意思，作为连词，是“但是，（不是...）而是”的意思，我们要严格把好形式关，避免使其有歧义。

例如这道题，如果but后面不加 are的话，就会产生歧义“because they enhance reproduction or survival, but simply random by-products”除了...的副产品以外，他们增加繁殖或存活。