[求助]Prep2-21~~~~~~~~~~~~~~~~~~~~~拜谢

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

选了D，错了，请教大家，指正。

答案是c

选C.此题考察的是逻辑表达。

注意it所指。正确的逻辑关系是：科学家们掌握了如何合成“生长激素”，这个“生长激素”是从人的尸体中提取的。正确的逻辑际关系中it指代的是“生长激素”，而不是“合成的生长激素”。所以D错。 the growth hormone和synthetic growth hormone的区别。因为科学家得到的样本是“the growth hormone”。

哈哈哈，有意思。

支持这个解释，牛！