The composition "My Discovery" is 400 words, at the fourth grade level, and it is very urgent.

At breakfast, I peeled a boiled egg and put it upright on the bottle mouth. Half of the eggs are immersed in the bottle. I used to press the egg by hand, but when I pressed it into the bottle, it broke into several pieces. At this moment, it suddenly occurred to me: Can I put this egg in the bottle without damaging it? I asked my father this question, and he thought for a moment and said, "No problem."

Dad found some waste paper and kneaded it into a ball. He lit the paper with a match and carefully threw it into the bottle. Dad said to me, "Look at this, I'm going to do magic!" " "He put an egg with a shell on the bottle mouth, pressed it gently with his hand, and heard a bang, and the egg completely fell into the bottle.

I was very surprised. "What's the trick?" Dad said, "The trick is …" Dad was interrupted by his mother before he finished. "Don't worry, you'll know the trick when I do a little experiment."

I saw my mother find a glass bottle with a smaller bottle mouth, a lighter and a piece of paper. During the preparation, I asked my mother, "Mom, what experiment are you going to do?" Mother replied: "The experiment I want to do is' cupping'. As for the answer you want to know, after reading my experiment, you will certainly understand. " Mother rolled up her sleeves and approached the paper with a lighter. Then, as soon as she pressed the lighter, the paper burned. Mother unhurriedly put the paper into the bottle. After a while, the flame in the bottle went out, and my mother buckled the glass on her left arm in lightning speed. After a while, mother turned her hand to the downward direction of the bottle, but the bottle didn't drop! This is amazing. Mom asked me to try to pull the bottle down. I tried, but I, a "Hercules", couldn't do it.

When my mother saw my monk Zhang Er, she smiled and explained to me, "When the paper burned, the oxygen in the bottle was used up. When the oxygen is used up, the flame goes out, and the jar is pushed into the skin by external air pressure and firmly adsorbed on the skin, so that the bottle will not fall. In the egg pushing experiment, because the egg blocked the whole bottleneck, the outside air could not enter the bottle to replace the consumed oxygen, so the air pressure in the bottle dropped and the egg was sucked into the bottle. "

There is science in life and science is in life. As long as we explore and study, any mystery will be solved.

I found my father's "vault"

"I found it! I found it! I found my father's' vault'. " I whispered to my sister.

"You brag, you can't find out, because dad's money belongs to mom, and dad has no money to hide." Sister said.

"It's money, I saw it with my own eyes." I went on to say.

"You said." My sister looked at me doubtfully and squeezed these words out of her mouth.

I cleared my throat and said, "At six o'clock this morning, I got up to pee and found my dad sneaking around in the living room. I quickly squatted down and hid behind the sofa to watch. I saw my father put a hundred-dollar bill through the gap behind the TV and then went to bed. I sneaked a look and found that there was really money in the gap. I didn't move and went to bed again. "

Hearing this, my sister ran to see it. If so, she smiled happily.

After seven o'clock, my father got up, so I went to ask my father. Dad wouldn't let me tell mom, so I promised dad. Because I know that my father's money will always be in my mother's hands, and my mother asks my father to be "justified" in his money, while my father's asking my mother for money is like a "loan", which requires not only repayment but also "interest". Dad had no choice but to hide the money himself. I asked my sister to keep my father's secret, and my sister agreed.

Alas! Mom! You keep your father too tight. After I make money, I will give my dad money every month so that he can be handsome.

I found ┅ ┅)

In the fourth grade, in a science class, the teacher told us that paper can be used as a pot to boil water. After listening to it, I thought the teacher's words were ridiculous: how can paper be used as a pot? Didn't the paper burn before the water was hot? But the teacher is serious, not like lying to us. So I came home from school to do experiments to confirm the results. z

I went to the coal house to find a wire, clamped it on a small shelf with pliers, then found a piece of paper, folded it into a "small basin", filled it with water, put it on the shelf, then found a candle, put it under the shelf, and finally I lit it. I stared at the water in the basin: two minutes later, the bottom of the basin was dark. After two minutes, the water was a little hot. Two minutes later, a miracle happened-the water boiled! The paper is not broken! I can't believe my eyes. I checked several times, but the paper still didn't break! soul

The success of this experiment has strengthened my curiosity. What is the reason? Why won't the paper break? I decided to find out! I came to the school library to check the information and finally found the answer: it turned out that the temperature was at work! Because the temperature required for paper to burn is 130 degrees, and water only needs 100 degrees, so the heat is completely absorbed by water, and the paper certainly can't burn! phR)/

This experiment proves that some things that seem strange to you will not be strange as long as you try to find the answer! Qa^

I found a way to do business.

Many people will do business as adults, but my business experience began in the second grade. The taste of doing business is fresh in my memory.

In the second grade, the school turned the playground into a lively "flea market" for small businessmen to do business freely. Hearing this news, my mother and I began to think hard, choose goods and advertise the store. We first designed the advertising words-choose "I" to ensure your satisfaction. Then began to beautify the decoration, after some twists and turns, designed a rough but warm advertisement.

The next day, I walked into the flea market with my advertisements and "small commodities" that I had treasured for many years. At first I saw that everyone's business was deserted, and I was no exception. I don't even have half a customer. Just when I wanted to give up, an old lady came to have a look. Suddenly, her eyes fell on my hardcover version of Tinker Bell Cat. "yes." While the iron was hot, I enthusiastically explained to her: "This book is very interesting, and the children like it very much ..." After listening to my explanation, the old woman had a smile on her face: "This story book is great, just right for my grandson. He will be very happy! How much is it! I bought it! " I saw the customer come to the door, blushing like a red apple, and shyly said, "1 yuan." "Wow, only 1 yuan, that's great! Here. " At that time, my heart was full of joy and I was really happy.

With a good start, I will be more energetic! I shouted, thinking about how to expand the momentum. I had a brainwave: why not have a prize sale? So, I picked up a pen, wrote "buy one get one free" on the sign, and then shouted: "Come and buy! Buy one and get one free until it's finished. It's now or never. " Now my career is really in full swing, and I am too busy to breathe.

Doing business is really interesting. After the competition for the word "Shang Hai", I found a way to do business: first, to create momentum; Then we should provide customers with warm, meticulous and caring services; Finally, we should change the operation mode to stimulate the market. These principles have a good enlightening effect on my future life journey.