The World Health Organization says it needs to see clear evidence of sustained community transmission of the swine flu virus from person-to-person in at least two regions of the world before it raises its alert to the phase six pandemic level.

VOA: standard.2009.05.14

And they remain two atoms per ion pair discretely bombing around in the gas phase.

每个离子对中仍含有两个院子,分散得分布于气相中。

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Phase Two, in the middle Pleistocene phase--700,000 years ago.

第二阶段,在更新世的中期,约七十万年前

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And then V minus the excluded volume term is equal to RT. Two parameters, this is the attraction between two atoms or molecules in the gas phase.

以及V减去一个排斥项,等于RT，两个参数，这是气体状态下两个原子,或者分子之间的吸引力。

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