In the process of observing nature, I happened to find that the shape of the trunk is almost round-an empty cone. Why is the trunk conical? What are the benefits of a conical trunk? In order to discuss these problems, I made more in-depth observation and analysis.

With the help of my tutor, I consulted relevant materials and learned that the stems of plants have the functions of supporting plants and transporting water and other nutrients. The stems of trees are mainly composed of vascular bundles. The supporting function of stem is mainly borne by wood fibers in xylem. Although the stems of woody plants will become thicker year by year, in a certain time range, the number of woody fibers in the stems is certain, that is, the cross-sectional area of the stems is certain. Then, based on the assumption that the cross section of the trunk grows into different shapes, we design experiments to explore the reasons and advantages of conical trunk.

Through experiments, we find that when the cross-sectional area and length of (1) are fixed, the vertical supporting force of triangular columnar objects is the largest and the lateral bearing capacity is the smallest; The vertical supporting force of cylindrical objects is not as good as that of triangular cylindrical objects, but the lateral bearing force is the largest; (2) For trunks with the same mass and different shapes, the short conical trunk bears the largest wind force; (3) Wind is a natural phenomenon, which affects the cross-sectional shape and height of trees. The approximate cone-shaped trunk has a low center of gravity, and the huge root system is connected with the earth, so the center of gravity drops lower and the stability is greater; (4) The cross section of the trunk is round, which can reduce the damage, has stronger mechanical strength and can resist the wind attack. At the same time, under the action of the wind, the bending degree of the trunk is similar everywhere. No matter which direction the wind blows, the resistance of the trunk is similar, and the trunk is not easy to be damaged.

The above experiments reflect the laws of nature, and nature enlightens us: (1) A columnar object with a triangular cross section has the greatest vertical supporting force, and its shape can be used in buildings, such as angle steel; (2) A circular object with a circular cross section has the largest lateral bearing capacity, and similar building materials can be found everywhere, such as TV towers and telephone poles.

In the process of observation, experiment and analysis, I gradually explained and revealed the mystery of conical trunk, increased my knowledge, and combined my knowledge with practice, which not only consolidated my knowledge, but also improved my interest in learning, and initially learned the scientific observation and analysis methods.

I went to the future world

I came to the future world in a space-time spaceship.

I jumped off the boat and walked into an orchard. In front of me, there is a big round orange room. I suspect this is grapefruit, but it's too big! It's really a grapefruit from afar, which really opened my eyes. There are such big grapefruit in the world. A scientist came out of nowhere and said to me, hello, little friend, let me introduce you. This is a giant grapefruit that I invented. Because of the increasing population in China, I ate a lot of small grapefruit. In order to avoid wasting too much grapefruit skin, I invented the giant grapefruit.

A community only needs to buy a giant grapefruit. I looked at the big and nice giant grapefruit and swallowed. He saw me. He said, well, I'll treat you to grapefruit today. Just when I was thirsty, I jumped three feet.

He took out a small ladder less than one meter from his pocket. I thought, how can I climb up such a small ladder? He took a remote control out of his pocket and pressed the button. The ladder suddenly became very high. He and I climbed the ladder and thought, I really have something delicious. He took a chainsaw from his back and cut the grapefruit. He gave me a spoon and I gulped it down. It is so sweet and cool! I just ate less than a small seed in the grapefruit and I was full. I couldn't eat any more, so I climbed down slowly. From a distance, I only ate a small pit in the grapefruit, which was really delicious.

I walked around the orchard and saw huge apples, huge peaches, huge cantaloupes and so on. ...

I said goodbye to the old man and walked out of the orchard. In front of me is a big house. When I walked in, I was shocked. There are many cartoon characters in it, including Doraemon, Bear, Flower Fairy, Astro Boy ... and of course, my favorite woody cherry. An inventor came out of a small room. He said to me, hello, my name is Ada. I am the owner of this house and the creator of these cartoon characters. They want to play with the children. Now the state stipulates that only one child can be born. Playing alone is lonely and boring, so I created them to make the only child no longer lonely and boring. Please choose some to play with you. I chose Woody Sakura, Astro Boy, Flower Fairy and the beautiful girl warrior Shui Yue Bin.

The flower fairy made me a beautiful dress with flowers. The upper body is pink and the lower body is blue. I like it very much. She wished me more and more beautiful and lovely. Take me to visit the Crystal Palace. She made me a bracelet with crystal and I put it on. She hopes my heart will always be kind, clear and pure. Astro boy took me to the blue sky. I never knew the sky was so blue and the clouds were so white. He wants my dream to fly. Woody Sakura and I played the koro card together. Kuloka has bubbles, alternating cards, bright cards and so on. She wants me to continue fighting like Kuloka, and I have a good time.

Before I knew it, it was dark. I managed to get on the spaceship with their blessing and fly back to modern times. I think I must do something beneficial to others and future generations!

Ode to the Motherland

The Long March is a huge and rich spiritual legacy left by the China Party to the Chinese nation. The Long March left a magnificent chapter of our party, our army and the people along the way. The Long March left behind the essence of the producers and the Chinese nation. The Long March left a brilliant example in the military history and war history of our army. The Long March is not only an epic and colorful movement in the history of the party history army, but also a swan song in the history of human spirit and the spiritual wealth of our party, our army and the Chinese nation.

Send off your comrades and embark on a journey. It's a long way to go in Xiu Yuan, so it's hard to sprinkle camel bells all the way. The mountains are stacked and the water is vertical and horizontal.

Against the wind and water, we aim to live up to the people's feelings. Yes, we come from the people, rooted in the people, and the people raised us. Everything we have is given by the people. The kindness of parenting, the kindness of parents, is as heavy as mountains and deep as the sea. Sailing in the sea depends on the helmsman! For decades, whenever China's revolution and construction are at an important juncture, it is because of the leadership of the CPC Central Committee and the guidance of great Mao Zedong Thought, Deng Xiaoping Theory and Theory of Three Represents that the great ship of revolution and construction can bypass numerous dangerous beaches and reefs and advance triumphantly in stormy waves along the revolutionary channel of Marxism-Leninism. Party, dear mother

Tears beside Luohu Bridge.

Mature thoughts on the edge of Xiangjiang River

Like green leaves, they bear sunlight and rain.

Like a son in a mother's arms.

The red flag was thrown into the west wind.

The red flag guides the sons and daughters of China wave by wave.

The red flag is the flag that leads the world trend.

I sing the passion of the season.

I appreciate the bright colors on the red flag.

Huangshan Yellow River is my intoxicated dream.

The Great Wall of the Yangtze River got into his heart and didn't want to wake up.

No matter how far the dream is.

No matter how heavy the ends of the earth are.

We all have the same heart.

I remember that many people were deeply moved when the beautiful melody of sending the Red Army ten miles came from the TV series "Long March" hit by CCTV. This sincere and moving song seems to let us see the touching scene of the military and civilians. Let the spirit of the Red Army live forever, and let the melody of "Ten Send the Red Army" live forever! Who helps us turn over and who helps us to be liberated? Who helped us build the highway and who helped us build the bridge? Is the people's liberation army, is a relative, is the * * * production party, is the savior. Fish, water and songs, military and civilian family!

When we shed tears, it was our motherland that gave us solid support.

When we were injured, it was the home that our motherland gave us.

Motherland, you are the sun cast by Chinese sons and daughters with their lives, shining on our hearts and never falling!