请教GWD1-41

seventree

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.

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

还有人来看这题么？我选B，没有那么多复杂的理由，看时态，Leaching这种方法到现在还是在应用的。没必要用was/had been.

seventree

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.

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

还有人来看这题么？我选B，没有那么多复杂的理由，看时态，Leaching这种方法到现在还是在应用的。没必要用was/had been.

shouyang12

C

GMAT阿驴

B错因为  minerals 后少了,  well established 修饰歧异

LunarLin

我选E.

ljyxjt

E，只有E的时态是对的。

amber0919

amber0919

Ｅ时态有误．过去完成时表示在过去某点前发生并已经完成．表示已经停止了的动作．该题没有这个意思．过去普遍存在，并没有停止．

windson9

!!!!!!!!!!!!!!!c

dreamchaserdan

E