The human body is a living machine, and, like all machines, it needs “fuel” to supply it with energy. This is provided by the food we eat. But how much do we need to stay healthy? The energy value of food is usually measured in calories(卡). A calorie is the amount of heat required to raise the temperature of 1 kg of water by 1℃. The number of calories people need per day is different, as the picture shows. Also, the number of calories you use at any one moment normally depends on the activity you are in. For example, you need more calories for standing than for sitting, more for running than for walking, and so on. The energy in food is in the form of three kinds of chemical materials—carbohydrate(碳水化合物), protein(蛋白质) and fat. Carbohydrate provides 3.8 Cal /gm of the energy, protein 4.0 Cal/gm, and fat 8.8 Cal/gm. Each food contains different amounts of these materials, as the round pictures show. (P= protein C= carbohydrate F=fat) 小题1:How many calories are needed to raise the temperature of 5kg of water from 35℃ to 90℃?
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异乡的暴风雨 幼苗
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1年前
anyhow,i have a heart of human
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你能帮帮他们吗