【正确答案】正确答案：it means his nose can identify various tastes and flavors．

【答案解析】解析：根据题设定位到第4段第4句。该句后面的“He is capable of identifying 450 different tastes and fla-vors．Constant explains that the mouth，which can only taste four things—salt,sweet，acid and bitter—is‘stupid’in comparison to the nose”是对“Constant is also a…‘nose’”的解释和说明，由此可知Constant的鼻子可以识别不同的气味和味道，而人的嘴巴只能品出四种味道。所以回答本题时可化用原文说法，并将具体数字450种抽象化，便可得出答案It means his nose can identify various tastes and flavors。