ps: Thank you to the queen of heaven and the king of the earth, joycf, the magic knife boy kills, ‖ is hopeless, zzxx1212, the big devil who loves to sleep for the reward, as well as the monthly ticket of the face is not white, the wind and the clouds are Xiaoxiao, the soul is dead, zzxx1212, and the brothers and sisters who voted highly praised, thank you to the mountain village!

In the evening, after eating, everyone gets together to chat and watch TV.

And at this time, a piece of news caught everyone's attention. The host inside reported that tomorrow there will be an abnormal sandstorm in the capital area, reminding citizens to wear masks when they go out.

"Alas! Everything is good here, it's just this annoyance, and every now and then there is a sandstorm. Chen Wu said.

Some of the children were not afraid, but looked forward to it, wanting to see what the legendary sandstorm was like. In the past, in books, on TV, in class, etc., teachers explained that sandstorms were very powerful.

And some children were misled by the previous teachings, the legendary sandstorm was overwhelming, and everything would be buried in the ground, and some little ones had a small face and panicked: "Then let's go quickly!" When you go home, you won't be afraid. ”

When the others heard this, they all cried and laughed, hiding from a sandstorm to hide" "Going back to my hometown thousands of kilometers away, will it be an exaggeration?" It seems that it is to let the children see the sandstorm, so that they don't understand, and they think that it will really destroy the world!

And some children reacted quickly and immediately expressed their opinions: "Don't be afraid, there is a Great Wall, it will block them." "In this little one's heart, the Great Wall is the patron saint of everything.

Everyone listened and secretly wiped their sweat. These little ones are really imaginative! In the face of wind and sand, the Great Wall is not useless, but it is very small. On the contrary, the "Great Green Wall" will work. This is what we call the Three-North Shelterbelt.

The construction project of the three-north shelterbelt system is a grand project that benefits the present and the future, and is not only a major project in China's ecological environment construction, but also an important part of the global ecological environment construction. Its construction scale, speed and efficiency are more than the "Roosevelt Prairie Forestry Project" of the United States, the "Stalin Plan to Improve Nature" of the former Soviet Union and the "Green Dam Project" of the five North African countries, and are known as "China's Great Green Wall" and "the world's best ecological project" in the world.

"It's okay, you don't have to go home so soon, we just don't go out tomorrow. There is a layer of dust floating outside, and it will not bury the capital. Ye Caiping comforted the child and said".

The other children looked at Teacher Liu. Why is the secret path different from what you said to the teacher?

Teacher Liu also blushed and coughed lightly: "Hmm! Tomorrow's sandstorm is not big and not dangerous. Tomorrow's plan is cancelled, and when the sandstorm is over, we'll go out again. ”

He can't tell his children what he said before. It's all exaggerated. The consequences are exaggerated. How much shame is this? Affect the serious image of your teacher.

Actually, Mr. Liu didn't say it wrong, but he didn't say it in detail. Sandstorm is a collective term for sandstorms and dust storms, and the consequences of sandstorms are naturally serious, and it is indeed possible to bury a place underground, which is not an exaggeration. A dust storm is just a dust storm, and when a dust storm occurs, the place is usually shrouded in flying dust. If it's serious, it's like fog, and you can't see the way forward. And the capital area. It's usually a dust storm.

The increasingly serious sandstorms in China are mainly caused by irrational land development and unreasonable farming. With the increase of population and the inadequate management of relevant parties, a large amount of land has been reclaimed in Northwest and North China, overgrazing grasslands, and natural vegetation has been artificially destroyed, resulting in a large amount of bare and loose land, which provides a large number of sand and dust sources for the occurrence of sandstorms

Healthy sandstorms.

"Uncle Chen, are there often sandstorms in the capital?" A child asked curiously.

Chen Wu nodded without thinking: "How many times a year will there be?" As far as he knows, in recent years, the number of sandstorms in the capital has been greatly reduced, from 60 or 70 a year more than a decade ago to only 3 to 5 a year now.

However, sandstorms are generally concentrated around April, and sandstorms at this time are relatively rare.

"Then why isn't the capital buried underneath?" The other child immediately asked. Several times a year, it stands to reason that the capital has been buried many times.

Chen Wu's eyes widened suddenly: "That bastard told you that the sandstorm even buried the city?" ”

Seeing Chen Wu looking over, Chu Jiacheng glanced at Teacher Liu, and said very innocently: "I haven't said such things to them!" "It's really depressing, every time something happens, it's always the first thing that comes to mind.

Chen Wu was taken aback when he saw Chu Jiacheng's gaze on Teacher Liu, and quickly shut up, he had already found that Teacher Liu was glaring at him.

The next day, the little guys in the "Portable Mountains and Rivers Map" actually got up early one by one, and the reason was to watch the sandstorm, which was really painful. Speaking of going outside, as soon as people hear it, they will know that you hillbillies have never seen the world.

I saw that there was already a layer of yellow fog outside, and the whole sky was gray-yellow, and I couldn't see far away.

"This is a sandstorm, isn't it?" One of the children muttered, visibly disappointed by the legendary sandstorm. In their minds, it should be overwhelming, and they can't see their fingers.

Some of the children reached out, and after a while, their hands were covered with flying dust. Teacher Liu drove them back one by one, running out in such weather is not good for your health, don't you see that others are wearing glasses and masks, and some have to wear a silk scarf around their heads? This level of armament is better than the outfit of fighting devils back then.

Seeing that many little guys were a little disappointed, Zhou Furong said: "You should be lucky that this sandstorm is not big, if it is a big one, it will be pressed like a mountain, and the day will be like night, and you can't see anything." ”

When almost all sandstorms come, we can see black walls of wind and sand moving rapidly in the direction where the wind is blowing, getting closer and closer. From a distance, the wind and sand wall is as tall as a mountain, very much like a city wall, and it is the vanguard of the arrival of the sand and dust "entertainment show".

When a strong sandstorm occurs, the wind is very strong due to the wind blowing above level 8, which can roll up stones and sand. As more and more sand and dust flew into the air, the dense sand and dust covered the sky, blocking the sun and making it impossible to see anything for a while, as if at night.

In addition, there are often two kinds of imagination. When the black wind blows, the air near the ground is very unstable, and the heated air below rises, and the surrounding air flows to replenish, causing the air to carry a large amount of sand and dust to roll up and down, forming countless dust balls of different sizes in the air.

The upper layer of the aeolian sand wall is often yellow to red, the middle layer is grayish-black, and the lower layer is black. The yellowing and redness of the upper layer is due to the fact that the dust in the upper layer is thin and fine-grained, and the sunlight can almost pass through the dust and shoot down. The lower layer of sand and dust has a large concentration and coarse particles, and the sunlight is almost completely absorbed or scattered by the sand and dust, so it is black. Where the wind and sand walls moved, the sky was changing from light to dark. This is caused by the light passing through a band of sand and dust of varying thicknesses and thicknesses.

"It's a pity I can't see it." The children said with depressed faces.

As soon as these words came out, Chu Jiaqiang and the others were even more depressed than them, I am afraid that only the children would hope that these phenomena would be freshmen, as if they were at home in the south, and they hoped that it would rain for a long time and be freshmen, and it would be best to come to the typhoon, so that they would not have to go to school. (To be continued.) )