阅读理解。      

     Basketball stars are usually tall. The stars of other sports are sometimes short. Some of the best

football players are not very tall. Short people often have better balance than tall people, so they do not

fall over very often. In some sports the players must have good balance, for example, table tennis and

running.     

     You do not need long legs to run fast! Some of the fastest runners in the world are not very tall. Some

are tall and some people are short. There is no medicine to make people grow taller or to make people

shorter.    

     Today young people in many countries grow taller than their parents. This is because they eat better

food today. Good food can help children grow.

根据短文内容，下列问题。

1. How many different sports do we talk about in this passage? What are they?

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2. Is there any medicine to make people grow taller or to make people shorter ?

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3. Why are some young people taller than their parents today?

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