There is only one content of the earth text.

Original text of primary school textbook "Only One Earth"

According to the astronauts who were lucky enough to fly into space, when they roamed in the sky, they looked at the earth from a distance and saw a crystal-clear sphere with blue and white lines intertwined and covered with a thin layer of water-blue "tulle". The earth, the mother of human beings and the cradle of life, is so beautiful, spectacular and amiable. However, the earth is a planet with a radius of only over 6,300 kilometers. It is like a boat in a starry universe.

Compared with the vast universe, the earth is small. It's only this big, and it won't grow any longer. The surface area of the earth is 5 1 10,000 square kilometers, and the land inhabited by human beings only accounts for about one fifth of it. In this way, the range of human activities is very small.

The natural resources of the earth are also limited. Take mineral resources as an example, it is not given by God, but formed by geological changes over millions or even hundreds of millions of years. The earth is selfless, and it generously provides mineral resources for mankind. However, if mining is not controlled, there will be less and less mineral resources on the earth.

The water resources, forest resources, biological resources and atmospheric resources needed by human life could have been regenerated and contributed to human beings for a long time. However, due to the wanton destruction of natural resources and the indiscriminate use of chemicals, human beings are not only unable to regenerate, but also cause a series of ecological disasters, posing a serious threat to human survival.

Some people will say, isn't there a lot of space? There are countless planets there. When the earth's resources are exhausted, can't we move to other planets?

Scientists have proved that there is no second planet suitable for human habitation at least within 40 trillion kilometers centered on the earth. Humans can't expect to move to other planets after destroying the earth.

Yes, scientists have put forward many ideas, for example, building an immigration base on Mars or the moon. However, even if these ideas are realized, it is far away. Besides, how many people can live?

"Our earth is lovely and fragile!" This is the sigh of astronauts traveling in space and witnessing the earth.

There is only one earth. If it is destroyed, we have nowhere to go. If all kinds of resources on the earth are exhausted, it will be difficult for us to replenish them from other places. We should seriously protect the earth and its ecological environment. Let the earth better benefit our future generations!

The earth is the mother of human beings and the cradle of life.

According to the description of the astronauts who were lucky enough to fly into space, the earth they saw in space was a beautiful, crystal-clear and only living planet, surrounded by a thin layer of water-blue tulle. The earth has always made selfless contributions to human beings, but because human beings don't know how to cherish, develop unrestrained and destroy at will, not only the natural resources of the earth are getting less and less, but also a series of ecological disasters have caused a threat to human survival. For example, in July 1995, an incident occurred in our country: several factories discharged excessive sewage and smoke into the ocean and atmosphere, which led to a large amount of acid rain decline and destroyed a large area of forests and crops. This not only pollutes the environment, but also causes serious losses to natural resources.

Our earth is both lovely and fragile. Students, scientists have already proved that there is no second planet suitable for human habitation within 40 trillion kilometers of the universe centered on the earth. Humans can't expect to move to other planets after destroying the earth.

There is only one earth, citizens of the earth, wake up! Let's start with protecting every grass, tree, mountain and water around us and take action. Let's protect the earth, our home!

This lesson introduces the knowledge about the earth from the perspective of human existence, and expounds the truth that there is only one earth for human existence. The significance of protecting the ecological environment of ball games is expounded. The text shows that the earth is facing the threat of resource depletion from the aspects of the smallness of the earth in the universe, the narrow range of human activities, and the random exploitation or destruction of the limited natural resources owned by the earth. Then, the results of scientific research prove that when the earth's resources are exhausted, there will be no second planet for human habitation. Finally, it is concluded that there is only one choice for human beings, and that is to protect the earth and its ecological environment carefully.