Then the thesis compares and analyses the two common methods, and finds out least three defects in internal rate of return method: it has an improper opportunity cost hypothesis;

文章继而对这两种常用决策方法进行比较分析，发现内部收益率法至少有三大缺陷，即它有一个不适当的机会成本假设；

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In California, the Department of Toxic Substance Control brought charges against a geothermal plant for improper disposal of cartridge filters used to remove inorganic solids from the return water.

FORBES: Google Funded Project Confirms Vast Potential for Geothermal Energy