求助 GWD1-41

yuki_real

GWD1-Q41:
Leaching, the recovery of copper from the drainage water of mines, as a method of the extraction of minerals, it was well established as early as the eighteenth century, but until about 25 years ago miners did not realize that bacteria take an active part in the process.



A.as a method of the extraction of minerals, it was well established

B.as a method of the extraction of minerals well established

C.was a well-established method of mineral extraction

D.was a well-established method of extracting mineral that was

E.had been a method of mineral extraction, well established
为什么选c呢？？是因为简洁吗，可是as early as 之前总觉得应该加well established,请教中。。。

yuki_real

谢谢啦

花子落落

一般A of B形式，主语在于A，后面的修饰部分就是修饰A吖~~~
C中前面已经有了a well-established method，还要well established干嘛~