The traditional methods for treating As-containing wastewater, such as physical and chemical ones, have some shortcomings: high cost, serious second pollution, and hard to be applied.

前言：含砷废水的传统处理方法如物理法和化学法的不足之处是费用高、二次污染大、工程化程度小。

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youdao

It's hard to learn a concept, but once you understand it, that knowledge can be applied repeatedly.

学习一个概念绝不容易，但一但你真正理解了它，知识便可以重复利用。

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When it comes to manufacturers serving those markets, "it's going to be very hard to get leverage for change" because consumers typically haven't applied as much pressure on brands as in Western countries, she said.

WSJ: 3 Die in Cambodia Factory Collapse

Rigorous, hard, fact based Cost-Benefit Analysis has to be applied if the EZ is not to create another cash drain.

FORBES: Enduring Euro Or Currency Collapse

The particular area in which such people make their mark might be determined purely by the kind of environment or skill to which they were exposed and how hard they then applied themselves.

ECONOMIST: Who wants to be a genius?