An unforgettable lesson in 500 words

An unforgettable lesson.

Since I stepped through the doors of primary school, I have taken a lot of classes, including lively Chinese lessons, interesting math lessons, and mystical nature lessons. One of the third-grade nature lessons is still fresh in my memory and still remembers it vividly.

It was a Tuesday morning three years ago, near the end of school, and Ms. Hong gave us a special homework assignment, which was to prepare two eggshells for each person to go home. Hearing the teacher's assignment, we were all stunned, and some guessed that maybe the teacher was going to let us use it for handicraft; Some guessed that maybe the teacher was going to let us draw easter eggs; I guess Mr. Hong must let us do the experiment.

Looking at our puzzled looks, Mr. Hong showed a "mysterious" smile, as if to say: "The mystery of the next class will naturally be revealed."

At the end of the class, everyone was anxious for Mr. Hong to quickly uncover the mystery, Mr. Hong guessed our thoughts, and said slowly: "Students, please put the eggshell on the table, we are going to use the eggshell to do an experiment." "I was so surprised to hear that I was going to do an experiment, and I guessed Mr. Hong's intention.

Students, do you think this eggshell, is the arched side easy to break or the dented side? ”

The students said in unison: "The sunken side is easy to break."

Why? "People don't know why.

Teacher Hong continued, "Please take out the eggshells you have prepared, and let's do an experiment together." ”

I put the eggshell on the ground with the arch side facing up, raised the pen in my hand and placed it at a height of about 5 cm on the eggshell, and with a gentle release, the pen hit the eggshell. Alas! The eggshell was unharmed.

I thought: Maybe I'm not doing it! Or try again.

This time, I simply aimed the tip of my pen directly at the arch of the eggshell and killed it hard. Strange eggshells are still intact. I looked around, and my classmates looked puzzled just like me.

Seeing our blank appearance, Mr. Hong smiled and said, "Students will test the concave surface of the eggshell again, and then compare the differences." ”

We turn the eggshell upside down, so that the sunken side of the eggshell is facing up, and with a light stroke of the pen, the eggshell breaks. It turns out that the sunken surface of the eggshell is so vulnerable.

Teacher, why is that? Some of the students got tired of it and started asking questions of the teacher.

Mr. Hong picked up an eggshell on the table of the students in the front row and said, "This is the principle of thin shell structure, because the arched surface of this structure can counteract the action of external forces, the structure is stronger. The Great Hall of the People in Beijing and the Sydney Opera House have made full use of this principle, and of course, the principle of thin shells is everywhere in our daily lives.

Invite students to discover and excavate. ”

Over the years, I have also slowly discovered hard hats, windshields of cars, ......It all comes from the principle of thin shell, and Mr. Hong's class left me with a lot to think about.

The stars were shining and blinking, and I stopped under the starry night sky, which reminded me of the scenes of that lesson.

I remember one Chinese class, we were learning to accumulate the use of reading and memorization, when we understood the composition of the interval, the teacher said to us: "Now I draw whoever can't memorize it will be deducted points in the group." "Okay!

We speak in unison. I suddenly felt uneasy in my heart, thinking: If the teacher draws Tan Xiaotong, she will be deducted points if she can't recite it, what should I do?

The students who were drawn by the teacher passed the test one by one. Tragedy struck, and the teacher shouted: "Tan Xiaotong, you come to carry the sesame seeds on your back, what is next?"

Tan Xiaotong stood up, and my heart also lifted, she lowered her head and said nothing. I looked at the other classmates, and saw that some of them were talking quietly with their tablemates, some were grinning and baring their teeth, looking sarcastic, and some were looking left and right, thinking of coaxing ......As for the students in our group, some were anxious, some were so angry that their faces were red by Tan Xiaotong, and what was even more interesting was that some students learned from Western countries to draw a cross to pray for a miracle, and I also sweated for Tan Xiaotong, and thought: Why did the teacher order a student who shouldn't have ordered?

Knowing that she won't carry it. Unexpectedly, a miracle really happened. Tan Xiaotong mustered up his courage, raised his head slightly, and said in a slurred manner

Saving ......Section height. "Okay, please be seated! The teacher was very happy and continued:

There is nothing difficult in the world, I am afraid that there are people with hearts, Tan Xiaotong will carry it, which shows that she has worked hard and paid, and we can't look down on others. Looking at each one with colored glasses, this is an act of disrespect for others and unfairness to others, and I hope that the students can get rid of their bad habits. I lowered my head, regretting that I had inadvertently hurt a fragile heart, and decided to take off my colored glasses when looking at people in the future.

That Chinese class made me, a student with relatively good grades, deeply regret and blame myself, and deeply realize that people will have shortcomings and advantages, but they will never be perfect.

The teacher's earnest words kept ringing in my ears and constantly motivating me to move forward. In the future, no matter whether one's conditions are better than others, everyone must take off their colored glasses and treat them fairly, so as to be respected and welcomed by others.