Paragraph 1
     Scientists have learned a lot about kinds of food people need. They say that there are several kinds of
food that people should eat every day. They are: (1) green and yellow vegetables of all kinds; (2) citrus
(柑橘) fruits and tomatoes; (3) potatoes and other fruits and vegetables; (4) meat of all kinds, fish and
eggs; (5) milk and foods made from milk; (6) bread or cereal (谷类), rice is also in this kind of food ;
(7) butter, or something like butter.  
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     People in different countries and different places of the world eat different kinds of things. Foods are
cooked and eaten in many different kinds of ways. People in different countries eat at different times of
the day. In some places people eat once or twice a day; in other countries people eat three or four times
a day. Scientists say that none of the differences is really important. It doesn't matter whether foods are
eaten raw or cooked, canned or frozen. It doesn't matter if a person eats dinner at 4 o'clock in the afternoon
or at eleven o'clock at night. The important thing is what you eat every day.
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     There are two problems, then, in feeding the large number of people on earth. The first is to find
some way to feed the world's population so that no one is hungry. The second is to make sure that people
everywhere have the right kinds of food to make them grow to be strong and healthy.