Fourth grade interesting math questions and answers·

Fourth grade interesting math questions and answers·

How to make money
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After reading that there is only one earth, what is your preliminary understanding of the earth?

The earth is the only living sphere, very fragile, we need to protect it

13. There is only one earth
It's dark

According to the introduction of the astronauts who were lucky enough to fly into space, when they roam in the sky, they look at the earth from afar. What they see is a crystal ball, with blue and white lines interlacing each other, surrounded by a thin layer of water blue "gauze". The earth, the mother of human beings, the cradle of life, is so beautiful, magnificent and amiable
However, compared with the vast universe, the earth is small. It is a planet with a radius of only 63 million kilometers. In the starry universe, the earth is like a boat. It is only so big that it will not grow up
The earth's natural resources are also limited. Take mineral resources as an example, it is not God's gift, but formed after millions of years or even hundreds of millions of years of geological changes. The earth is selfless, and it generously provides mineral resources to mankind. However, if it is exploited without restraint, it will accelerate the depletion of mineral resources on the earth
The water resources, forest resources, biological resources and air resources needed by human life can be regenerated continuously and contribute to human beings for a long time. However, because human beings destroy natural resources at will and abuse chemicals regardless of consequences, not only can they not be regenerated, but also cause a series of ecological disasters and pose a serious threat to human survival
Some people will say, isn't the space very big? There are countless planets. 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 beings to live on, at least within 40 trillion kilometers around the earth. Human beings can't expect to destroy the earth and then migrate to other planets
Yes, scientists have put forward many ideas, such as building an immigration base on Mars or the moon. But even if these ideas are realized, they are still far away. Besides, how many people can live there?
"Our earth is so lovely, but it's too easy to break!" this is the exclamation of astronauts when they travel in space to see the earth
There is only one earth. If it is destroyed, we have no other place to go. If all kinds of resources on the earth are exhausted, it is difficult for us to get supplement from other places. We should carefully protect the earth and protect the earth's ecological environment. Let the earth benefit our future generations better!

Does atmospheric circulation mean thermal circulation?
Are the concepts of general circulation and thermal circulation the same, or are they both different? What is the difference between general circulation and thermal circulation,

Thermal circulation is the air movement caused by the uneven heating of air under ideal condition (no geostrophic bias, no seasonal variation and even surface)
The atmospheric circulation is a model which tends to be a real atmospheric movement, considering the geostrophic bias caused by the earth's rotation (the classical model is three circle circulation), the seasonal movement of solar direct point, the uneven distribution of land and sea on the earth's surface, the thermal difference between land and sea, and many other factors