※ 引述《A2GMAT (A兔GMAT)》之铭言：
: ※ 引述《fangmole (Dean)》之铭言：
: : 74.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.
: : (C) because they enhance reproduction or survival, but
: : (D) because they enhance reproduction or survival, but are
: : 想询问实战上C、D的解题方法/观念
: : 看了Ron及语法笔记的解释仍然不太明白为何选C会造成ambiguous
: : 感谢各位版上神人释疑！！
A2 老师的解释也说不通。
: 这题主要是考but对比关系直接（direct）和间接(indirect)的概念,
: 我把培训班讲义部分重点先列出, 这里在对比关系前的结构如下：
: S+V+O adv.conj S+V+O, but S+V+O
: 若选C这里but对比关系有两种可能
: 1. many biological traits are not the products of natural
: selection BUT simply random by-products
: of other evolutionary developments
: 2. many biological traits enhance reproduction or survival
: selection BUT simply random by-products
: of other evolutionary developments
: 因为对等连接词but对比关系可能是针对最前面的主要子句作对比
: （S+V+O adv.conj S+V+O）, but （S+V+O）
: 也可能只是在副词子句中的对比
: S+V+O adv.conj （S+V+O）, but （S+V+O）
74.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.
原题目中的
the products of natural selection,
favored due to their enhancement of reproduction or survival,
是由非限定关系子句
the products of natural selection,
which are favored due to their enhancement of reproduction or survival,
转换过来的非限定修饰语，原文根本就没有副词子句。
而 favored due to their enhancement of reproduction or survival
只是个过去分词词组，哪来子句？所以绝对不可能出现第二种对比方法。
: 所以补出are只是在强调针对最前面的主要子句作对比,
: 让对比关系更clear, 我想强调一点, C的文法没有错, 句意也合理,
: 只是D选项更better, 也就是句意更清楚
同时下面这种写法
2. many biological traits enhance reproduction or survival
selection BUT simply random by-products
of other evolutionary developments
是把题目都改了，来适应自己最后的解释，GMAT的修辞是不能这样玩的。
: 另外想提醒一点, 不是看到not....but....就一定是在考not A but B,
: 可能还要考量子句和子句的对比关系;还有我建议大家培养独立思考能力,
: 不是Manhattan讲的东西都一定是神物, 因为再怎么样Manhattan也不是出题者,
: 我看论坛也发现有些解法有问题,只是比较少, 任何问题都应该按照修辞
: 的观念来探讨, 真理不就是越辩越明吗？
提醒大家 not ... but 在这里一定是考相关连接词的平行结构。
来欣谢忠理老师
: ※ 引述《fangmole (Dean)》之铭言：
: : 74.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.
: : (C) because they enhance reproduction or survival, but
: : (D) because they enhance reproduction or survival, but are
: : 想询问实战上C、D的解题方法/观念
: : 看了Ron及语法笔记的解释仍然不太明白为何选C会造成ambiguous
: : 感谢各位版上神人释疑！！