请教prep07语法一道

笨蛋加油

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  
答案C，知道其他的不对，可是答案C怎么看着这么不顺眼。。。it had to be painstakingly removed  small amounts from这是个什么结构？remove A from？那个small amounts 怎么如此别扭？？？

笨蛋加油

没人解答~~~

笨蛋加油

eshopaholic

把它简化看看：

It has to be removed from the glands.
It had to be removed (in small amounts) from the pituitary glands (of the human cadavers.)

kyle7

LZ好像少看了一个in吧～