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      There is nothing more i to life than the sun. W the sun, all living things on the earth would die. The sun is a star. In the sky there are t of stars like the sun. They are as large as the sun and as hot as the sun. At night you can see many stars, but in the day you can o see one star-- the sun.

      The sun is much n to us than any other star. That is w it looks the biggest and brightest of all the stars. The distance (距离) of the sun from the earth is as m as 150,000,000 kilometers. Most stars are thousands of light-years afrom the earth.

      Do you know what a light-year is? N in the world travels faster than light. It travels 300,000 kilometers per second. And one light-year is the distance that light can travel in one y.