颜色的变化是由章鱼皮肤上的两种不同的细胞造成的，主要是皮肤表面的色素细胞。

The color changes are executed by two different kinds of cells in the octopus' skin, mainly by color cells on the skin's surface call chromatophores.

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然而，羽毛的稀疏分布也使得皮肤表面形成相当大量的侧向空气流动，从而可以通过对流进一步散热。

The sparse distribution of the feathers, however, also allows considerable lateral air movement over the skin surface, thereby permitting further heat loss by convection.

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头发是在皮肤表面下微小的袋状即毛囊中产生。

Hair is made in tiny pouches just under the skin's surface, known as follices.

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These are very deep lesions that go not just on the surface of your skin like a blister would, but down into the dermis or deeper layers of the skins, as well.

这些伤非常深,它们不仅像水泡那样存在于皮肤表面,还深入到真皮层或者皮下更深的地方

耶鲁公开课 - 生物医学工程探索课程节选

So, they developed this bifurcated tool, which would be appl--you'd put the stuff on the surface of the tool and then you'd scratch the skin in a certain way so that you could produce sort of a reproducible introduction of the vaccine into the skin.

所以他们发明了一种分为两叉的工具,把疫苗抹在这种工具表面上,然后以某种方式在皮肤上刮,这样就能将疫苗,重复不断地引入到皮下

耶鲁公开课 - 生物医学工程探索课程节选