The Earth

1      The earth means many things to the people wholive on it. To a farmer, the earth is rich soil. To a road builder, the earth means mountains of hard rock. For a sailor, the earth is water as far as the eye can see.     A pilot’s view of the earth may include part of an ocean, a mountain, and patches of farmland. An astronaut speeding through space sees the earth’s round shape and the outline of land and oceans. Each of these different views helps describe the earth but none really tells what the earth is.

2      The earth is a huge ball covered with water, rock and soil, and surrounded by air. It is one of the nine planets that travel around the sun. The earth is the home of mankind and many other living things. Animals and plants live almost everywhere on the earth’s surface. They can live on the earth firstly because it is just the right distance from the sun. Living things need the sun’s warmth and light for life. They also must have water to live. The earth has plenty of water that covers most of its surface.

3     A thin layer of rock called the crust forms the earth’s surface. Under the crust is hot liquid rock. A ball of hard metal lies at the center of the earth.

4     The earth is always moving. It spins like a top and travels around the sun at the same time. We use these two movements of the earth to measure the lengths of a day and a year.     One day is the time it takes the earth to spin around once. One year is the time it takes the earth to travel once around the sun. The earth’s spinning motion makes the sun appear to move from east to west, and causes days and nights on the earth. As the earth moves around the sun, the night sky changes slowly. Some groups of stars are visible in the night sky, and other groups disappear into the day sky.

5     To call people’s attention to the importance of protecting our mother earth, Earth Day was created in 1970. Since then, on every April 22, people all over the world show their love for their common home — the earth.