1. Requirements for an explanatory essay about the formation of aurora: 400 words

Aurora

There are many kinds of aurora, colorful, different shapes, and extremely beautiful. There is no other phenomenon in nature that can compare with it. It is difficult for any colored pen to depict the dazzling light that plays and changes in the cold polar air. Sometimes the aurora appears for a very short time, like holiday fireworks that flash in the sky and disappear without a trace; sometimes they can shine in the sky for several hours; sometimes they are like a ribbon, sometimes like a flame, sometimes like a picture A huge colorful screen; some are colorful and ever-changing; some are only silver-white, like cotton wool and white clouds, solid and unchanging; some are extremely bright, covering up the brilliance of the stars and the moon; some are very light, as if they were one Bundles of green silk; some have a single structure, shaped like an arc, showing light green and reddish tones; some are like colored silk or ribbons thrown to the sky, flying up and down, flipping; some are as soft as gauze scarves, fluttering in the wind, showing It produces purple and crimson colors; sometimes the aurora appears on the horizon, like the dawn of dawn; sometimes the aurora is as bright as a camellia, a fiery red; sometimes the aurora is densely packed together, like a curtain; sometimes it shoots out many beams of light, like a peacock spreading its tail. , butterfly wings flying.

Edit this paragraph Aurora production

Production

Aurora (Aurora or Polar light or Northern light) appears over the high magnetic latitude areas of the planet. It is a kind of Brilliant and colorful luminescence phenomenon. The Earth's aurora is produced by the high-energy charged particle flow (solar wind) from the Earth's magnetosphere or the sun that excites (or ionizes) molecules or atoms in the upper atmosphere. There are three conditions for the generation of aurora: atmosphere, magnetic field, and solar wind. All three are indispensable. Auroras not only appear on Earth, but also on other planets with magnetic fields in the solar system.

Early Views

This has been a celestial mystery that has been speculated upon and explored for many centuries. In the past, the Eskimos thought it was the torch that guides the souls of the dead to the aurora

heaven. In the 13th century, people thought it was light reflected from the Greenland ice sheet. In the 17th century, people called it the Northern Lights - the Northern Lights (the same light seen in the Antarctic is called the Aurora Australis). With the advancement of science and technology, the mystery of the aurora is becoming more and more known to us. It turns out that this beautiful scenery is a work performed by the cooperation between the sun and the atmosphere. Among the forms of energy created by the sun, such as light and heat, is an energy called the "solar wind." The solar wind is a stream of charged particles ejected from the sun. It is a powerful stream of charged subatomic particles that can cover the earth, so it is in a plasma state. The solar wind flows around the Earth and hits the Earth's magnetic field at a speed of about 400 kilometers per second. The earth's magnetic field is shaped like a funnel, with its tips facing the earth's north and south magnetic poles. Therefore, the charged particles emitted by the sun settle along the "funnel" of the earth's magnetic field and enter the earth's polar regions. The upper atmosphere at the poles emits light after being bombarded by the solar wind, forming auroras. What forms in the Antarctic region is called the Aurora Australis. What forms in the Arctic region is called the Northern Lights. 2. An essay introducing the Northern Lights. 50 words

The term "Aurora" comes from the Latin word Eos.

Legend has it that Eos is the "dawn" in Greek mythology. The incarnation of the Greek god Titan, the sister of the sun god and the moon goddess. From the moment humans first looked up at the sky and saw the northern lights, the northern lights have always been a "mystery".

For a long time, people have developed their own legends about the aurora. The Eskimos believe that "the aurora is a torch used by ghosts and gods to guide the souls of the dead to heaven." The indigenous people regard the aurora as the appearance of gods and firmly believe that the fast-moving aurora emits gods. The sound of stepping in the air will take away people's souls and leave behind doom."

For a long time, there have been different opinions on the cause of the aurora.

Some people believe that it is a fire burning on the outer edge of the earth; some believe that it is the light reflected from the sky after the sunset; still others believe that it is the polar circle ice and snow that absorbs and stores sunlight during the day and then releases it at night. An energy.

This celestial mystery did not have a physical and reasonable explanation until humans sent satellite rockets into space. Essentially, aurora is an optical phenomenon stimulated by the operation of atoms and molecules in the uppermost layer of the Earth's atmosphere (100-200 kilometers above the ground).

Its formation has three major elements: the sun, wind, earth's magnetic field, and atmosphere. The so-called "solar wind" is a kind of energy that the sun continuously emits into the universe. It is composed of electrons and protons.

Due to the intense activity of the sun, countless charged particles are emitted. When the stream of charged particles is shot towards the earth and enters the scope of the earth's magnetic field, it is affected by the earth's magnetic field and enters the north and south at high speed along the earth's magnetic field lines. In the upper atmosphere near the magnetic pole, it collides with oxygen atoms, nitrogen molecules and other particles, resulting in the phenomenon of "electromagnetic storm" and "visible light", which becomes the "aurora" that attracts much attention. . 3. A 500-word essay on what the sunset looks like when it turns orange

As the sun sets in the west, the beautiful sunset gradually spreads over from the horizon. The setting sun also changed from half of the moon cake to a crescent shape covered by the sunset, and finally fell asleep.

The sunset dyed the western sky red. It shines slightly on every corner. At this time, the sunset looked like a shy little girl, just painted with a layer of orange. The clouds in the sky were blurred and took on various forms. Some are like lambs, running on the grass; some are like doves of peace, flying freely. The sunset was very mysterious. After a while, it turned into a light red. At this time, it seemed that everything in the world was shadowed by the sunset, as if it was floating among the flowers. The sea is quiet. The sunset was a little reluctant and tried its best. The color made people feel unpredictable and unforgettable.

The black feeling is gradually approaching us, but the sunset has not given in. He still insists on his beauty. The breeze blew by, as if I could feel the end of the sunset. On the horizon, the slightly reddish clouds also dispersed. He reluctantly put on the black gauze and walked away.

It was getting dark, and blurry light spots flashed in the sky, like elves jumping on it. The night is also lit up by lights. Against the backdrop of the illuminated city, the night is even more beautiful.

I recalled the beautiful sunset and couldn't help but admire its beauty. The morning glow is magical, and I think the sunset glow is even more beautiful. Because his beauty is natural and simple, and I know that he has an unyielding spirit. Don’t we need to do this in our study and life?

As I thought about it, I looked at the sky and was intoxicated. ...... 4. Write a 500-word essay on appearance description

Appearance description When I was 6 years old, I suffered from alopecia. There was not even a hair on my head. The children laughed at me and called me "bald monk". , whenever this happens, I cover my ears with my hands, as if my head is exploding.

It wasn’t until I was 8 years old that I recovered from my illness. I looked in the mirror and saw that my hair had grown back. Later it became black and shiny. I was no worse than anyone else. No one called me “bald” anymore. Monk". Grandma was sitting next to me combing her hair, frowning and mumbling to herself.

Her hair is surprisingly abundant, densely covering her shoulders, chest, and knees, and hanging down to the ground. It is jet black and glows with blue light. She picked up her hair from the ground with one hand, held it up, and with great difficulty inserted the sparse wooden teeth of the comb into the thick locks. 5. A 500-word essay describing thunderstorms for sixth grade

Bao Jianan, a fourth grader at Yinghua Bilingual School in Zhaodong City, Heilongjiang Province, "Boom, boom, boom—" there were several bursts of thunder, and the black clouds were like a group of galloping and roaring wild horses. .

Layers of it spread over the top of the head, getting thicker and thicker, and getting lower and lower, as if one could pull off a piece by standing on the top of the building. The sun was so frightened that it didn't know where to hide. It was like someone had turned the clock to night, and the sky and earth were pitch black.

It’s going to rain! We ran back to the classroom. Unfortunately, there was another power outage. I couldn't see the teacher's face two tables away, let alone read the words on the blackboard.

Crackling! Ding-ding-ding-ding! Raindrops as big as copper coins hit the glass windows and iron tiles rhythmically. "Crack!" Another big thunder! It seemed as if the Tianhe River had exploded, and heavy rain started pouring down.

A streak of lightning flashed across, and the branches swayed crazily in the wind and rain. Clouds of white mist rose from the roof, and the water from the eaves poured down like a mountain waterfall.

After a while, the streets and yards turned into a vast ocean. Cars passing by splashed up walls of water more than one meter high, and strong winds stirred up layers of water waves. At this moment, we seem to be sitting on a big ship sailing through the wind and rain.

The sky is getting brighter, the rain is gradually getting lighter, the drizzle is like milky white fog, and the woods and grasslands are flowing with refreshing green. The clouds have dispersed, the sun has come out, everything on the earth seems to be filtered, the fresh air carries the fragrance of flowers and plants... Instructor Zhang Jun Leiyudongshan 2nd Primary 3 (5) Class Suchen Today, the weather is extremely hot and sultry, making people feel breathless. Out of breath, I thought it would rain soon.

After a while, the dark clouds in the sky seemed to be about to collapse. Lightning and thunder swept across the sky, as if the entire sky was split. The wind was not to be left behind, it blew loudly. It blew up the dancing leaves and twisted the tree roots. It started to rain heavily, and the big raindrops kept falling like broken pearls. The rain fell heavier and heavier. Soon the rain falling on the ground merged into a stream, laughing, singing, and dancing towards the ground. As I ran forward, the raindrops were like pearls, sprinkled on the river, causing ripples on the calm water.

The clever fish jumped out of the water, as if to suck the pearls. The rain whipped the buildings, trees and asphalt roads like a whip.

The rain kept falling, like thousands of needles and threads, sewing the sky together tightly. The heavy rain is like the face of a child who cries when he cries and laughs when he cries.

The rain stopped immediately. The air was exceptionally fresh, the leaves became even greener, and a rainbow appeared in the blue sky in the distance, like a giant arched bridge spanning the sky. between the horizons. The gusts of wind blew over and it was very cool.

Teacher’s comment: The author of this article has careful observation and clear organization. According to the order before the rain, during the rain, and after the rain, grasp the characteristics of the thunderstorm and describe it more specifically.

Thunderstorm (Composition) He Haiyan, Grade 4, Xiaohe Township Central Primary School, Ganzhou District Thunderstorms in summer come at any time. After lunch, I sat in front of the window and did my homework. I felt that the weather was a bit cold and it was about to rain.

In an instant, the wind was strong and the sky was filled with dark clouds. Then it started to rain.

The rain was getting heavier and heavier, and it was raging. The rain fell like countless lines, washing the rows of trees in front of the door.

Suddenly, the rain blew into the window with the wind and wet the homework book. I quickly closed the window. It rained heavily.

I looked out through the glass window, and the sky and the earth seemed to be hung with an extremely wide bead curtain, covered in gray. The rain dripped on the tiles of the house, and the water splashed everywhere. The entire roof seemed to be shrouded in a layer of mist, and the leaves, flowers and grass were all green and shiny.

The rain gradually subsided, the sun emerged from the clouds, and the rays of light shone on the earth. The earth was extremely fresh. The rainbow hangs like a sky bridge in the vast sky.

I opened the window, and the scent of earth came to my face. A group of birds fly freely under the blue sky and rainbow. They fly higher and farther... (Instructor: Xing Limin) Thunderstorm Jiang Ziwen, fourth grade of Dongtai Experimental Primary School The sound of thunder came from a distance.

After a while, it started to rain. The big raindrops began to be sparse, then became larger and heavier, and then fell more densely.

Strands of rain woven into a "rain net", covering the entire city. I ran downstairs and rushed into the vast rain curtain.

"Wow, it's raining heavily!" I suddenly felt much closer to nature.

Countless raindrops were jumping around and jumping around: some drew vertical lines in the air, some were "domineering", and some simply jumped on the roof.

Whether they are falling sideways or floating diagonally, their lives are short-lived and disappear in an instant; their lives are eternal - they are integrated into the earth wholeheartedly. ! Climbing high and looking into the distance, one can see a thick haze of smoke. The hazy houses seemed to have become a fairy tale city made of building blocks; the trees were also misty, and the green color was faintly dim.

The wind shook the branches of the tree enthusiastically, and the tree waved its arms happily and danced with the wind! At some point, the rain quietly stopped and the dark clouds gradually dispersed. In the sky, the sun showed its face, and a beam of golden light shot towards the four. 6. A 500-word essay describing winter rain

The continuous rain for several days has brought inconvenience to everyone’s travels.

People are feeling a little depressed when encountering such weather as the Chinese New Year is approaching. At noon, I took a taxi home from Longtan Bridge.

Since I was walking in a hurry in the morning, I didn’t bring an umbrella. At this time, I can only accept the "baptism" of heavy rain.

When I finally stopped a taxi, the down jacket I wore had become a "raincoat". The taxi driver was a "sister". Seeing my embarrassed look, he smiled and said, "It's raining so hard, so I don't even bring an umbrella when I go out." I smiled sheepishly, and after giving my home address, I He just lowered his head and patted the rain off his body.

When I suddenly looked up, I found that I was already at the pedestrian street. Hey, why did "de's sister" drive here? Isn't this "the opposite direction"? So, I asked "de's sister": "I went to Wanhong Wucun, why did I drive here?" "De's sister" patted her own He quickly apologized: "I'm sorry, I'm sorry, I heard the wrong address."

After that, he immediately turned the car around and started calculating the price again. While waiting for the red light, "Sister" was still patting her head in self-reproach.

If I hadn’t slurred my words in a panic, I think she wouldn’t have gone through so many unnecessary mistakes. My face turned red. When I got home, "Sister's" self-blame look always appeared in front of me.

It is really rare for her to use such a sincere tone and sincere service when facing a child! I was very touched and felt grateful to be respected. I regretted it so much. Because I was eager to go home, I neither took the taxi invoice nor read the license plate number clearly.

Thank you to this "sister". Your excellent service attitude is like a ray of sunshine in the winter rain, which warms my heart. Thank you! I write this article to wish you, my sister, and all my brothers and sisters, a safe journey. 7. A 500-word essay about thunderstorms

In the afternoon, a strong wind suddenly started blowing outside. Cocks and dogs were crowing everywhere in the village, and the house became dark. It's going to rain. The leaves shook violently, and there was a "rumbling" sound in the distance, as if coming from the ground.

I looked out the window and saw that the sky was covered with dark clouds and the wind was blowing loudly. There were almost no pedestrians on the street, and only a few cars were seen passing by quickly. After a while, heavy rain poured down outside. The window of my house rattled due to the wind, and my mother quickly locked it. During the thunderstorm, I couldn't turn on the TV, computer, tape recorder, or repeater... I had no choice but to draw.

Another gust of wind shook people's eyes, and I didn't know whose window was open, and there was a "pop" sound of broken glass. There were wet marks of raindrops on the ground, gradually getting bigger. The thunder became louder, as if it was inciting the rain: everyone, jump down! The rain started getting heavier. The sound of thunder became clearer, and grandma said: This is the most dangerous thunder. The sound of thunder "click" and "click" is really like what is written in "Journey to the West", with Thunder God and Thunder Mother dancing with sledgehammers in the clouds to direct. The lines of lightning became thicker and thicker. When there was thunder, a bolt of lightning pierced the sky and penetrated into the ground. The sky became like daylight. The rain was intermittently, sometimes heavy, sometimes soft, the sound of "Hua Hua" gradually getting closer and farther away, I don't know when it will stop. Birds with nests have returned to their nests, and those without nests are hiding under the big trees, shaking off from time to time. The rain fell on his head, and then he hid his head deeply in his neck.

The speed of this lightning is getting faster and faster, appearing and disappearing quickly, like a little boy hiding with you. He is wearing bleached clothes. That kind of white is a color that is difficult to mix on the palette. He combined light yellow, orange, gray, and light-like white to form the color of lightning.

After the thunderstorm, the sky seems bluer and the air is fresher. Maybe the thunderstorm has washed them away! After a while, the lightning streaked toward the horizon, the wind ran into the distance, and the rain left quietly.

The ground in the village is very wet. In addition to the "tick" and "tick" dripping sounds, the flowers, grass, trees and trees there are covered with "new clothes" with crystal clear raindrops rolling on the leaves. , there are small puddles in front of the door, the dog is licking the water in the small puddles, the chickens come out of the chicken coop and look for food leisurely in the yard, and the birds fly away with "flutter" and "flutter" . Pigeons have also flown here, and the weeping willows by the river are even more beautiful.

What a thunderstorm! 8. A 500-word explanatory essay describing the Anyang River

The beautiful Anyang River

On Sunday, my father took me to play in the Anyang River.

Anyang River is so beautiful! Microwaves appeared on the surface of the river, and the water was as green as an emerald. The river flows eastward. It is true that the clear water flows eastward and returns here! Huh? There are a few ducks catching fish and playing on the water. Sometimes a small circle will appear on the river, where small fish are competing to jump high. There are people washing clothes by the river. On the south bank of the river is the beautiful Huanshui Park, and on the north bank of the river are green belts and leisure squares. The willow trees there have grown thin yellow leaves; the grass there has turned green; the winter jasmine there has blown a golden trumpet; the holly there has grown new green leaves. . There are so many flowers, plants and trees! It’s so beautiful here!

But there is a sewage outlet in the river, and dirty water keeps flowing out from there, forming a pollution belt dozens of meters long on the south bank of the river. There are all kinds of garbage floating on the river, including plastic bags, foam plastics, and paper boxes. There were cigarette butts, waste paper, and ashes left from the fire on the shore. These dirty things not only pollute the environment, but also affect the mood of tourists.

Anyang River is beautiful, but people's awareness of protecting the environment is still low, and some people throw garbage there unconsciously. Let's take action together, start from small things, don't litter ourselves, stop others from littering, and create a beautiful home together! 9. Write a 500-word essay about Niangniang Beach

Our hometown is located at the foot of Lushan Mountain. It is a good place with beautiful mountains and clear waters. We have many places of interest here, including the Lushan Forest Park, which has beautiful scenery. There are the eccentric Jiutian Cave, the fragrant and charming Peach Blossom Island, and the Cowherd and Weaver Girl Scenic Area separated by the Milky Way. But I think the most beautiful thing is the Waterscape Park.

Yiheyuan Waterscape Park is from Lushan From the Yiyuan Ape Man Site at our feet to the intersection of Mantis River and Yi River, the total length is 9.75 kilometers.

On a bright spring day, we came to the Waterscape Park. The river here was very clear, and for a while The breeze blows, and the river surface is sparkling, with ripples appearing in circles, and there are many small fish playing freely in the river. The flowers on both sides of the waterscape park are colorful, colorful, colorful, and colorful; the grass on both sides, There is a cluster here, a cluster there, full of vitality and green grass.

The waterscape park is even more beautiful at night! Hundreds of colored lights on both sides of the road open in the blink of an eye and are reflected in the water. Coupled with the neon lights and decorative lights of high-rise buildings, the colorful and brilliant lights form a "sea of ??lights, a world of light."

But the most exciting thing is the fountain in the Waterscape Park, look! The countless water columns spray evenly in the sky, and under the illumination of the light, they change into various patterns, like a curved rainbow; like a colorful pearl water curtain; like a beautiful peacock opening its tail; like a beautiful Fairy flowers... are really colorful, gorgeous and beautiful!

I am proud of the waterscape park with its “blue sky, green ground, clear water, bright lights and cool air”.