根据下面的提示，以“Air Around Us”为题，写一篇短文。（字数：100－120）

提示：
(1) 空气无色、无味、无嗅，但我们可以感觉到它的存在，因为风就是流动的空气。
(2) 没有空气人和生物不能生存，声音不能传播，飞机不能飞行。
(3) 空气中除水蒸气外主要含有氮气(nitrogen)和氧气。其中氮气约占78%，氧气约占21%。几乎所有生物都需要氧气，没有氧气就不能燃烧。

参考范文

Air Around Us

    Air is around us. We can not see it, smell it, or taste it. But we can feel the wind blow. We can see the wind move waves on the water, clouds in the sky, and tree branches. Wind is moving air.

    Without air we could not breathe. There could be no living plants or animals. Because sound travels through air, without air there would be silence. The movement of air can support a large, heavy plane.

    Air is a mixture of gases and water vapor. The most important gases in the air are nitrogen and oxygen. 78 percent of the air is made up of nitrogen, and about 21 percent of oxygen. Almost all living things use the oxygen in air. Fire cannot burn without oxygen.