题目内容：

缺词填空(10分)

There is nothing more i___1.____ to life than the sun. W__2.___ the sun, all living things on the earth would die. The sun is a star. In the sky there are t___3.___ of stars like the sun. They are as large as the sun and as h___4.____as the sun. At night you can see many stars, but in the day you can only see one star------ the sun.

The sun is much n__5.__ to us than any other star. That is w__6.____ it looks the biggest and brightest of all the stars. The distance (距离) of the sun from the earth is as m__7.___as 150,000,000 kilometers. Most stars are thousands of light-years a___8.__from the earth.

Do you know what a light-year is? N___9._ 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__10._____.