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 synthesize the growth hormone, it had to be painstakingly removed

B) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly

答案是A，

当时做题的时候看到A中后半句是被动，就直接先排除了。

我选了B， 请问B中的make a synthetic growth hormone是不是不好啊？

顺便在请教两个语法点

1 assistance of sth/sb 好还是assistance from sth/sb好

2，当只有两个东西的时候，我们用one, the other, 当有多个东西的时候我们用 one， others, 而不是the others，是不是啊？

请大家抽空看一下， 谢先

第一句我觉得growth 是修饰 hormone 的, 而且这里的动词应该是 synthesize.

assistance of sth/sb.

one, the other

some, others

B is acceptable in grammar except for the use of "a synthetic growth hormone" (which should be "the" instead.)

On a general basis, both "assistance of" and "assistance from" make sense; The use depends largely on the specific context.

The use of "one and the other(s)" explicitly conveys the exclusiveness in meaning.

lz你好，这里不是要看是否被动，逻辑意思关键：

选a， 句子是

Before scientists learned how to synthesize the growth hormone, it had to be painstakingly removed in small amounts from the pituitary glands of human cadavers。

选b，句子是

Before learning how to make a synthetic growth hormone, scientists had to remove it painstakingly in small amounts from the pituitary glands of human cadavers.

你仔细的看两个句子就可以看出，b句子里面，it指代的是a synthetic growth hormone，逻辑意思错了，是要合成生长激素，而不是制造一种合成的生长激素。

你其他的问题tomasy说的是对的。

In choice B, "it" doesn't have to represent the whole"a synthetic growth hormone", but the key word "growth hormone"!

Since there are only 2 types of growth hormone, natural and synthetic, therefore definitive "the" is needed ,rahter than infinitive "a".

With the assistance of sb, .....;

...to get assistance from outside....;

There is no set rule about of or from to follow assistance; the use is totally context-dependent!