十万火急！！！快考了，帮忙看看－个GMAT常考的语法点：not...but..的困惑

我一直认为not...but...引导的两部分应该平行，例如：

prep1-59.   A new genetically engineered papaya was produced not by seed companies who have been motivated by profit, which was the case with most genetically modified crops previously approved for commercial use, but university and United States Department of Agriculture researchers who allowed growers to use it free of charge.

(A) produced not by seed companies who have been motivated by profit, which was the case with most genetically modified crops previously approved for commercial use, but

(B) produced not by profit-motivated seed companies, the case with most genetically modified crops previously approved for commercial use, but

(C) produced not by profit-motivated seed companies, as was the case with most genetically modified crops previously approved for commercial use, but by

(D) not produced by profit-motivated seed companies, which was the case with most genetically modified crops previously approved for commercial use, but was produced by

(E) not produced by seed companies who have been motivated by profit, the case with most genetically modified crops previously approved for commercial use, but by

正确答案为C

但是，你们看看这道题：

prep1-73.   Evolutionary psychology holds that the human mind is not a "blank slate," but instead that it comprises specialized mental mechanisms that were developed as a way of solving specific problems human ancestors faced millions of years ago.

(A) the human mind is not a "blank slate," but instead that it comprises specialized mental mechanisms that were developed as a way of solving

(B) the human mind is not a "blank slate" but instead comprises specialized mental mechanisms that were developed to solve

(C) the human mind, instead of a "blank slate," it comprises specialized mental mechanisms that have been developed to solve

(D) rather than it being a "blank slate," the human mind comprises specialized mental mechanisms that have been developed as a way of solving

(E) rather than the human mind's being a "blank slate," that it comprises specialized mental mechanisms that were developed as a way of solving

正确答案为B

此题前后并不平行。

随后我又查了一下prep中有这种形式的句子，没能总结出套路，请大家一起讨论。

(A) the human mind is not a "blank slate," but instead that it comprises specialized mental mechanisms that were developed as a way of solving

(B) the human mind is not a "blank slate" but instead comprises specialized mental mechanisms that were developed to solve

(C) the human mind, instead of a "blank slate," it comprises specialized mental mechanisms that have been developed to solve

(D) rather than it being a "blank slate," the human mind comprises specialized mental mechanisms that have been developed as a way of solving

(E) rather than the human mind's being a "blank slate," that it comprises specialized mental mechanisms that were developed as a way of solving

正确答案为B

此题前后并不平行。

随后我又查了一下prep中有这种形式的句子，没能总结出套路，请大家一起讨论。

同意2楼的, 逻辑和语义上平行了, 形式就不那么重要了

当然这是在这道题的基础上, 能平行最好还是形式也平行

对阿, 后面一句也是一种平行啊,是两个谓语动词的平行: is 和 comprise,具体的说, d就是  is not ...but instead comprises

楼主如果不习惯这样看的话,可以把 is 颠倒过来啊,成了not is...but instead comprises ...

这样看应该很明显了吧

我做的时候也发现了not...but平行中的问题

我觉得如果not+be，be具体在not前后不太影响与but的平行问题

反而是此时but后面要接与be可以平行的动词比较关键

还有，prep中经常有be动词与实意动词平行的情况，尤其是and连接的最多（当然是相对而言选出的平行关系）

希望对lz有用~

我也马上就考了，一起加油吧！

谢谢大家的帮助啊，昨天问了这个问题后，我又仔细查看了一些资料，发现not...but...是要求结构平行的，正如大家所说be动词和实意动词本身就是一种平行，就如我举的第二题，be和comprise是平行的。确实在GMAT中not...but...的平行和be与实意动词的平行也是常考点。再次谢谢大家的帮助。

共同进步！战胜GMAT!