题目内容：

A very important world problem is the growth of population on the earth. The population of the world today is more than 6,500,000,000. That is a great number and we know it quite well. The important thing is not how large the population of the world is now, but is the rate (速度) of the growth. It is about 1.63% every year after the number of dead people has been taken away.

To give you some ideas of the birth rate, look at the second hand of your watch. Every second, four babies are born in the world. Another baby! Another baby! Another baby! Another baby! You can not speak quickly enough to keep up with the birth rate. The population is growing faster and faster. So it goes on, hour after hour. In one day, people have to find food for over 350,000 mouths more.

This great growth of population will make a big problem by the year 2013—there will be as many as 7,000,000,000 people on the earth! So this is one of the biggest problems that you are going to meet within your life.

根据短文内容，回答问题。

1.What’s one of the important world problems today according to the passage?

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2.What is the growth rate of population every year?

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3.What is the important thing about the population?

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4.From the passage, how many new babies are there to be born in a minute?

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5.What may be the population of the world by the year 2013?

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