[讨论]问道官14-41

notidgen

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.

 

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

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

3. was a well-established method of mineral extraction

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

5. had been a method of mineral extraction, well established

我选的E,答案：C,please explain

玻璃胶带

记得以前说过没有明显标示词一般不用过去完成时.

足球幽灵

E, well established离修饰对象太远,不如直接放在METHOD前好.而且,E明显改变了原来的意思: 原先as early as修饰的谓语was, 而E中,它的修饰对象成了established. MM是不是想到了时间顺序的问题,直接选了带过去完成时的? 其实两个有时间先后顺序的动作,不一定非要用过去完成时表现,这在OG里有例子