题目信息
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
参考答案及共享解析
共享解析来源为网络权威资源、GMAT高分考生等； 如有疑问，欢迎在评论区提问与讨论
本题耗时：
已选答案：
正确答案：
C:was a well-established method of mineral extraction
选项分析
(A) but前的分句有leaching、it两个主语，错误。
(B) but前的分句没有谓语。
(C) Correct；as early as the eighteenth century副词性短语修饰整个分句。
(D) that was修饰不清；而且as early as the eighteenth century时间状语无法做method的表语，应该使was变为助动词，后面加上一个过去分词作为谓语动词，如that was established as early as…。
(E) well established修饰method还是mineral extraction不清；过去完成时使用错误，had been表达的意思为"由过去的某一时刻开始，一直延续到过去另一时间的动作或状态"，文中并没有表达出"截止的时间"这个含义，故应该用一般过去时。
加入收藏
在线答疑
题目来源
GWD
