Before scientists learned how to make a synthetic growth hormone, removing it...

cppiod

在看这篇备考经验分享时，发现作者引用了这道题，但是对题目的解释不能令人信服。
帖子连接： http://forum.chasedream.com/thread-739174-1-1.html
题目如下：
Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.

A) scientists learned how to make a synthetic growth hormone, removing it painstakingly
B) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly.
C) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed
D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
E) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists

作者为了说明active/passive voice的使用要根据需要，做出了以下的讲解：
“原句(A)尽管语法错误，但表达的意思是清晰的，就说：到底是谁"remove it painstakingly"？这个问题作者没说，也不重要。强调的只是受体，而不是subject.
所以正确选项(C)的passive voice恰如其分。而错误选项(B)(D)包含的意思是scientists是"remove it painstakingly"的主语，这就是在原句基础上凭空添加了主语，distort the meaning. "

我同意作者的观点，并不是简单粗暴的总结说gmat喜欢active voice, 而是要根据表达准确，清晰，简洁的需要。但是作者对题目的解释有点差强人意。
于是我搜寻了一下，找到了一种自己可以信服的解释：

C,D语法上都没有问题，但是为何C对，而D不对呢? 原因是it的指代。
D 中 how to 的宾语是synthetic growth hormone, 意思是说在scientist没有学会如何make之前，要从尸体的脑垂体中小心的取下。但是synthesize意思是人工合成的，在自然界中是不存在的。因此如何选D，就出现了逻辑错误。
C 避免了这个错误，把synthetic 换成动词，这样宾语就成了 growth hormone, 后面的逻辑就正确了。
所以，并不是说"remove it painstakingly"的主语不重要或者D强加了主语，而是D项中it的指代不对。如果把D项改成： learning how to synthesize the growth hormone, scientists had to remove it painstakingly. D项也会变成可选项。

总体而言，C项不仅逻辑正确，而且it与所指代的对象growth hormone 位置也接近，表意清晰，所以是最佳选项。

dooooooooit

感谢！明白了！

PetitPete

顶楼主！               

Hayley_777

ron还有一个解释：
i.e., it implies that the people who learned to make the hormone were exactly the same people who previously had to extract it from human cadavers.
that's not a reasonable meaning, so you are absolutely right about eliminating on those grounds. nicely done.

Charline_chang

太回答太赞了  

destroyer

喜欢这个解释！

几许VV

顶楼主！               

SamKboardW

Notice how in choice D the test makers have changed the voice of one of the verbs. Now the sentence uses active voice “scientists had to painstakingly remove…”. This changes the meaning of the original sentence since it now adds new information that “scientists” actually had to remove the hormone. This information is not present in the original choice. And hence this choice by “adding” to the meaning of the sentence changes the meaning and hence is incorrect. Carefully notice that this sentence does not have any grammatical errors.

猪小王

支持lz的解释，觉得e-gmat和babybearmm，甚至manhattan gmat里面对于这道题的解释都差强人意。

这个题目表面看是active／passive voice，其实考点仅仅是it指代a synthetic growth hormone还是the growth hormone的区别。仅此，有时是我们被表面考点忽悠了。

angieyu12

楼主真棒！感谢分享！