Prep一题，大家来看下

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

(C) 正确，it指代the growth hormone（明确it的指代对象，是做对本题的关键）。
(D) it指代synthetic growth hormone不符合逻辑。

为什么D错？

不理解，it可以指代learning how to make a synthetic growth hormone分词短语？？

题意是:在科学家知道如何合成growth hormone之前,growth hormoone不得不从.....

C\D的差别在于it指代不同: C是指代the growth hormone,D指代synthetic growth hormone.显然,synthetic growth hormone是人工合成的,与后半句说的从胰腺里获得是逻辑矛盾的.

(哎,我也选了D. 逻辑意思越来越重要了.这种题老外肯定一看就看出来,而我们光看结构什么的了)

啊......原来是这样！！

没有仔细看题........谢谢啦

母语和非母语做题方法毕竟不同的啦