There are three types of seasonal influenza – A, B and C. Type A influenza viruses are further typed into subtypes according to different kinds and combinations of virus surface proteins.

有三种类型的季节性流感——甲型、乙型和丙型。 根据病毒表面蛋白不同的种类和结合情况，甲型流感病毒又进一步分类为亚型。

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So, then I can choose my favorite surface bounded by C.

那么我可以选择一个被C界定的曲面。

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So, just to get you used to this idea, I'm going to draw a level surface of a function of three variables OK, so it's a surface given by the equation w of x, y, z equals some constant c.

为了令你们习惯于这个想法，我画一个三变量函数的等值面,这是一个平面,由函数w=c给出的。

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The surface of the hepatitis C protease turned out to be flat.

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It is actually a completely mainstream view that doubling carbon dioxide, ipso facto, will only result in a net surface warming of about 1 degree (C).

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S.C Johnson has apparently started offering phone and electronic friendly sanitizers, which would not damage the phones surface or electronics.

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