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1. 这两种黑色素的比例决定了你的头发是多么红。

   zhè liǎng zhǒng hēi​sè​sù de bǐ​lì jué​dìng le nǐ de tóu​fa shì duō​me hóng.

   The ratio of these two types of melanin determines how red your hair is.

   Source: CCMatrix