Get knowledge composition

In daily study, work or life, many people have experienced writing and are familiar with it. The composition must focus on the theme and elaborate on the same theme. No rambling, lax theme or even no theme. Do you know how to write a good composition? The following is a collection of five knowledge compositions that I have carefully arranged. Welcome to share.

A few days before leaving school, my mother and sister and I went back to my grandmother's house to visit her and stayed for a few days.

Sitting on the bus, waiting for this long two hours, finally arrived at grandma's house! I got off the bus and ran and shouted, "grandma, grandma, we're back!" " "As I approached the door, I vaguely heard my little aunt's voice." Go and have a look. Looks like they're back "My cousin and I almost bumped into each other. She went out to meet us, but I went home in a panic. In this way, we met unexpectedly.

When it was cold in the afternoon, my mother led us to play by the field and walk along the road. My sister suddenly said, "Mom, let's go and play on the lawn over there!" " "Sister voice down, my cousin and I all burst out laughing. They both asked in unison, "What do you think that is?" My sister said, "lawn!" "Are you really stupid or playing dumb? That's a peanut field, not the lawn of your city. "My sister feels embarrassed and a little shy. My mother said, "don't laugh at her, because they have never seen anything in the farmland." "Yes, we have lived in the city since childhood, and we basically know nothing about the plants in the farmland.

We came to a green place again, and I said, "Mom, is this Schizonepeta?" At that, the two annoying brothers and sisters began to laugh again. They smiled and said, "That's sesame." My mother was afraid that my sister and I would be sad, so she said, "You two, stop laughing at them. They are like "silver rings" going to the countryside for the first time. How have you seen these things! " As soon as my mother dropped her words, I asked, "Mom, whose silver ring is it?" Mother said: "Silver Ring is a figure in Chaoyanggou of Henan Opera!" My mother said to me again, "Look carefully, what's the difference between Schizonepeta and sesame?" Oh! I looked at it carefully again, and it was a little different. At first glance, they look alike, but their leaves are a little different. The leaves of Schizonepeta tenuifolia look delicate and shiny, emerald green, and the leaves of sesame look rough and dark green. In this way, my mother led us to know many crops: peanuts, corn, soybeans, sorghum and millet. ...

In this way, I played a lot of jokes at the edge of the stadium in the afternoon, but I gained a lot of knowledge. This is a fruitful afternoon!

I was promoted to the fifth grade, and the school organized placement activities, which upset all our classmates. After the resettlement, I feel as if a new group has been established.

On this day, I was assigned to Class Two, Grade Five, and I had new teachers and classmates. The new semester, new teachers and new classmates are all unfolding in front of us.

Here, I'd like to introduce our new head teacher, Miss Jin Lin. She speaks affably. I heard that she is an experienced teacher and one of the top ten teachers!

Fortunately, Mr Jin Lin really lives up to his reputation. He takes us to swim in the ocean of knowledge every day, which makes us draw a lot of energy. As soon as he has time, he will take us to look up some information on the Internet. For example, don't forget the national humiliation, let us hate the aggressors, and we must strive for self-improvement. Don't forget the national humiliation. When we grow up, we must study hard to revitalize China and resist the shameful behavior of the aggressors who arbitrarily deprive and dominate our country. Therefore, we are all very grateful to Mr. Jin Lin for his inculcation and dare not slack off.

It was the teacher who taught us how to be a man, taught me how to be polite, and let us gain endless knowledge.

I still remember Mach said that the final exam was coming, and Mr. Jin's tired voice was hoarse, but he was still worried about us and refused to rest. The students were so distressed that they said to the teacher, "Teacher, please ask for leave and go back to rest. We will definitely review it carefully. " The teacher said, "no, the exam is coming soon." I don't want to influence everyone to study hard because of my voice. " In retrospect, this sentence has always touched me. We are really proud of having such a serious and responsible teacher.

At the end of this semester, I have a deep understanding of the word "responsibility". Everyone has his own responsibility, no matter how big or small, we need to do it wholeheartedly. At the same time, the gradual growth of knowledge broadens our horizons. Students, do you think this harvest is very gratifying?

Shakespeare said: "Books are the nourishment of the whole world. Life without books is like life without sunshine. Wisdom without books is like a bird without wings. " Indeed, books are our good friends, which bring us endless knowledge and endless gains. So, in order to increase the reading of extra-curricular books, my mother helped me choose a book, Fable Stories of China, which taught me a lot of life truths, among which, pulling out seedlings to help others, especially impressed me.

The story is about a farmer who pulled out all his seedlings in order to make them grow fast, but all the seedlings died. This story tells us that it is not enough to do things with good wishes, and it is even more useless to rush for success, and sometimes it will make things worse. Therefore, to do a good job requires not only confidence and enthusiasm, but also scientific methods, step by step, not foolhardy and not opportunistic.

So, I thought about our study and couldn't be eager to achieve success. Chinese, in particular, must rely on reading extra-curricular books and accumulating more vocabulary, which cannot be done in one day. The same is true of mathematical calculations. It is important to practice calculation every day, because the teacher says that calculation is the most basic in mathematics, and it needs to be accumulated over time to do better.

China people are everywhere in life. Without Chinese, you can't communicate with everyone normally, and everything you say will become a joke. Chinese is a bridge for people to communicate. In the sea of knowledge of life and study, Chinese is a quiet harbor, which will make you feel endless charm and daydream, so you must rely on a lot of reading to accumulate more Chinese knowledge. There is still a lot of mathematical knowledge around our life, which runs through all aspects of life. In real life, there are many math games, such as a child playing a math box filling game, and even there are many such math games in sketch. For example, "There are seven monkeys in the tree, one on the ground and several others." And so on, there are many examples in life. It is these interesting mathematics that make up the colorful pictures in our lives.

I love reading! I love books! It is my mentor and friend, and it has helped me acquire so much knowledge and become better and better! I think in the future, books will definitely help me gain more unexpected wonderful things! It reminds me that there is no shortcut to learning and there is no step away from success. Only by being down-to-earth and realizing it slowly can we achieve the final success!

On National Day, my mother and I visited Nanyang Science and Technology Museum, where I spent an unforgettable day.

The scenery is beautiful along the way, and the wide road is lined with trees. After an hour's drive, we finally arrived at Nanyang Science and Technology Museum. In front of us is a white six-story building, with the big gold letter "Nanyang Science and Technology Museum" on the front, shining in the sun.

When I walked into the gate, I was greeted by a huge white piano. I heard that this kind of piano can play music automatically, but unfortunately I didn't see this kind of piano playing with my own eyes. Then we went to the children's science room, where there were many interesting things: virtual skiing, tilting the cabin, the cabin changing color ... The most interesting things were tilting the cabin and visiting. I entered the inclined cabin and rushed sideways, but unfortunately I was pushed back by the airflow and almost hit the barbell. I felt dizzy when I came out. Let's talk about just visiting! After I went in, the background was dark red, and many things like meteoroids were hovering, which made people feel like they were in the Milky Way. Well done!

Then we came to the second floor. The most interesting thing here is the mirror maze. After I entered the maze of mirrors, I suddenly felt very dizzy. Where is the real channel, and where is the channel in the mirror, which makes it difficult for you to distinguish between true and false. I bumped into the mirror from time to time and walked for a long time before I found the exit. I played a few more times and finally figured out the mystery of getting out of the maze smoothly.

Finally, we came to the exhibition hall on the third floor. Here, I saw the robot solving the Rubik's Cube. I wanted to test him, so I handed him a Rubik's Cube several times. He glanced at it with his eyes first, then held the Rubik's cube in one hand and turned it with the other. In the blink of an eye, he found the Rubik's Cube. It's amazing!

I visited the Science and Technology Museum today and saw many interesting scientific phenomena and gained a lot of scientific knowledge. It was an unforgettable day!

From the science class, I know that the weather changes can be predicted according to "loach will surface before thunderstorm in summer". At the same time, I also think that in summer, before it rains, I often see the phenomenon of fish ponds or rivers "flooding" (that is, all the fish float into the water). Is this related to the hot weather, high temperature and lack of oxygen in water in summer? In order to get a thorough understanding, I am interested in "why do fish come out of the water before it rains?" Made a serious investigation.

First of all, under the guidance of the science teacher, I did the experiment seriously. I used three beakers, each containing 200 ml of water. The first cup was not heated. When the second cup is heated to 42℃ on the alcohol lamp, let it cool naturally. The third cup is heated to boiling, and then cooled. During the heating process, I found that when the water temperature reached 55℃, a small amount of bubbles appeared on the wall and bottom of the cup, indicating that the gas in the water began to stay. When heated to 75℃, it began to bubble rapidly. When three glasses of water cooled to room temperature, I put two small goldfish in each cup. I saw the goldfish swimming freely in the first and second cups, and the two goldfish in the third cup kept sticking their mouths out of the water and swallowing cigarettes. After more than an hour, two goldfish died one after another, indicating that the third glass of water lacked oxygen.

However, the temperature in summer generally does not exceed 40℃, and the water temperature is even lower. Therefore, I think the high temperature in summer is not the main reason why oxygen can't keep water. To this end, I made a further inquiry. Through repeated observation and reading of scientific and technological books and consulting scientific and technological materials on the Internet, I think there are mainly the following reasons:

1. The water temperature in summer is very suitable for microbial reproduction in water, which consumes a lot of oxygen in water.

The air pressure in summer is very low, especially before the thunderstorm. In summer, water gets less oxygen from the atmosphere, even less before the thunderstorm, and some gases (including oxygen) in the water will run into the air. Before a thunderstorm, fish often jump out of the water, because the low pressure makes the water anoxic.

Therefore, I think that the vigorous metabolism, increased oxygen consumption and low air pressure of various organisms in water in summer are the main reasons for hypoxia in water, not the high temperature in summer (because it is not higher than 55℃).