C/N ratio can be taken as a rooting index of elm tip.

碳/氮比率可作为白榆新梢生根的指标。

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By tracking this ratio over time, he can determine how long gas has taken to reach the surface and gain clues to the chemical, thermal, and mechanical state of the rocks the gas is passing through.

通过追踪该比率随时间的变化，他可以确定氡气到达地表需要花费多长时间，同时获得气体所通过的岩石的化学、热力学和机械状态。

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Cost-benefit ratio criterion----No activity where the present value of net benefits is less than zero should be taken.

成本效益分比率准则——净利润现值低于零的无活力地区应该被承揽。

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This means that the compression ratio of an ICE using ethanol can be taken up to 24:1 compression ratio before preignition begins to happen.

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It looks like a number of other ratio call spreads have taken shape on Yahoo!

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Ms. Warden already sees the benefit: "Only one kid has refused to have his picture taken and that is a better ratio than ever, " she says.

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