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题库 / Prep2008E2-SC-196
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.
as a method of the extraction of minerals, it was well established
as a method of the extraction of minerals well established
was a well-established method of mineral extraction
was a well-established method of extracting mineral that was
had been a method of mineral extraction, well established
请看讲解视频
Ron说，E错在两点，第一：时态不对，过去完成时表示leaching是过去的办法，现在不用了，但句中并没有表述这种意识； 第二，well established不应该作为非必要修饰语，个人理解从这个句意出发，前半句说这个方法好，后半句说发现这个方法的缺点，well established作为非必要修饰语，就削弱了整个句子的转折意味。
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