Well, if you get the combustion chamber hot enough, in point of fact, there are some reactions between nitrogen and the oxygen.

如果燃烧室的温度足够高的话，实际上在氮气和氧气之间,会发生一些反应。

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You ignite the food and burn it, and you see how many degrees centigrade the water gets raised, and that's the measure of calories.

点燃食物使其燃烧,然后观察水的温度上升了多少,就测量了这种食物的卡路里

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