1.为什么人的皮肤颜色不同? 你一定听说过黑、黄、红、白是人们常说的人种的肤色吧。不过人和人的肤色千差万别,而且常有交错现象。所以肤色之间的差别并不是“小葱拌豆腐——一青(清)二白”。比如说吧,有那么一些人,按人种他们属于白人,但实际上他们的肤色要比某些黑人还黑。究竟是什么给皮肤染上颜色的呢?因素有三个——皮肤的厚度,血液供给情况,尤其是皮肤中的色素,或叫染色物质。所有色素中最重要的一种是黑色素。这种色素的变化范围是从黄色到黑色。产生黑色素的细胞,就在皮肤的外层和内层之间。令人奇怪的是,不论什么人种,他们身上这种特殊细胞的数目 1. Why people’s skin color is different? You must have heard of black, yellow, red, white people often say that ethnic color it. However, human and human color vary widely, and often staggered phenomenon. So the difference between the color is not “green onion tofu - a green (clear) two white ”. For example, there are those people who, by race, are white, but in fact they are darker than some blacks. What exactly is the color of the skin? There are three factors - the thickness of the skin, the blood supply, especially the skin pigment, or dye. The most important of all pigments is melanin. This pigment varies from yellow to black. The melanin-producing cells are between the outer and inner layers of the skin. Oddly enough, no matter what race, the number of such special cells in their body