PREP 11 求解

11. 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. scientist learned how to synthesize合成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 have to be painstakingly removed by scientists

给的答案是C，我认为是D。因为我觉得主动优于被动。大家看呢？

这个题目我第一遍也选的D，但是现在觉得C比D好

感觉D的含义和C不同
D是说－科学家在学习合成hormone之前要先做另外一件事，没体现出原题的意思

不知对不对，请NN指点～！

还是不太明白，不过谢谢Abbigail_all的解答，我再想想。

偶觉得这个D最大的问题在于it的指代。

D里的it应该指代synthetic growth hormone（合成的 growth hormone）, 但从逻辑上讲应该指代the growth hormone，因为在合成以前是没有synthetic growth hormone的。

11. 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. scientist 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 have to be painstakingly removed by scientists

A: make a synthetic不如直接用动词synthesize有效率；后半句不是完整句，主从句关系不成立

B: before加过去完成时没有道理，learn这个动作实际应该在主句动词时间之后

C: correct

D: 从原句逻辑上看，句意中的hormone并不是被同一群科学家使用，而是表述了一种历史事件之后，hormone就可以被后来的所有人怎样怎样了，所以D从逻辑上有问题。

E: learning的逻辑主语不是hormone

注意：

1、             此题很难，要从逻辑上判断意思，以后遇到主动、被动时态的考点，一定要区分清楚施加对象和被施加对象的合理逻辑关系。什么时候用被动？当找不到主动动作发出者时，一定用被动！

2、             还有Before介词+doing，和让步状语从句的省略+doing的区别，When/while（时间）/if/unless（条件）/even though/even if/although（即使）/once＋名词/形容词/完整句

关于第2点，区别是什么呢？

斑竹的解释很经典，还有另外一个错误

before介词不能加doing（不构成让步状语从句），只能加时间点