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游客2023-11-07  17

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答案                         The Color of Snow
    Generally, the color of snow appears white. / This is because the light we see from the sun is white. / Most natural materials take in some sunlight. / This gives them their color. / However, when light travels from air to snow, some light is sent back, or reflected. / Snow crystals have many surfaces to reflect sunlight. / Yet the snow does take in a little sunlight. / It is this light that gives snow its white appearance. /
    Sometimes, snow may appear to be blue. / The blue light is the product of a long travel path through the snow. / In simple terms, think of snow as a filter. / A filter is designed to reject some substances, / while permitting others to pass through. / In the case of snow, all the light makes it through if the snow is only a centimeter thick. / If it is a meter or more thick, however, blue light often can be seen. /

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