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℃?
A．55.
B．175.
C．325.
D．275.小题2:Which of the following contains the most amount of calories?
A．Milk.
B．Rice
C．Peanuts.
D．Milk or peanuts.小题3:Who needs the most amount of calories each day?
A．A woman.
B．An office worker.
C．A farmer.
D．A boy aged 16.小题4:Which of following is True?
A．You need more calories for swimming than for mountain climbing.
B．A child aged 8 needs the same amount of calories every day as a man over 70 does.
C．A woman feeding baby needs over 4 times the amount of calories that a baby does.
D．Everyone needs the same amount of calories per day.小题5:This passage mainly tells us ______.
A．all the energy is in food
B．the human body needs energy
C．the number of calories depends on your activity
D．we must only eat peanuts to get calories
