Oil and water do not blend.

油与水不相融。

《牛津词典》

Oil and water do not mix.

油和水不相融。

《牛津词典》

Oil does not mix with water.

油不融于水。

《牛津词典》

Or you can steam them in a small amount of water or stir fry them in a small amount of oil.

VOA: special.2010.03.09

Here's a really simple example. Mixing of oil and water.

这有一个很简单的例子，水和油的混合。

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Now this behaves very differently in water because part of it is water soluble, this part is, it's a molecule that would like to dissolve in water and part of it is like oil, it doesn't want to dissolve in water.

它们在水中表现出十分不同性质,因为一部分是水溶性的,这一部分是,是一种可以溶于水的分子,而另一部分就像油,不会溶于水中

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Forty-nine vessels - oil skimmers, tugboats barges and special recovery boats that separate oil from water - were meanwhile working to round up oil, BP said.

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Oil and water may be hard to mix, but blending inputs creates a good salad dressing.

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As investors, we need to evaluate both in trying to distill this oil and water.

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