After finishing the first one, I started to read the second mathematics book also produced by Princeton University.
As a world-famous institution of higher learning, Princeton’s attainments and level in the field of mathematics are far ahead of MIT and no different from Cambridge University. The library of Peking No. 4 Middle School has purchased a considerable number of foreign high school textbooks and books, of which Princeton occupies the leading position.
Most of it.
There is a saying that after Yu Hua read the mathematics books published by Princeton, he had to sigh that the books published by the top famous schools have high gold content.
"Whoa whoa whoa."
There was a constant sound of turning pages, and many students frowned when they heard the sound. They were speechless when they saw Yu Hua turning the pages like a madman.
Damn, is this called reading?
It's obviously just for fun!
Even if it was Lin Wan, she had to raise her head when she heard the commotion, and looked at Yu Hua, who was looking attentively but kept flipping through the book. He glanced at the math questions in it, found it interesting, smiled, and went back to continue studying.
Time passed, and by ten o'clock in the evening, Yu Hua had finished reading three mathematics books, and his mathematics level had been greatly improved.
Five books, two mathematics textbooks, and three mathematics books.
"It's time to go, let's continue tomorrow." After finishing the third mathematics textbook, Yu Hua withdrew from his highly focused study state, and felt fainting in his head. This was a reaction of overuse of the brain, and he felt a little dizzy. He raised his watch.
I looked at the time.
When this feeling comes from your head, it means that you have reached your limit and it is impossible to continue learning.
It is meaningless if you force yourself to learn.
Time, 10:05 pm, efficient study time increased from six hours to eight hours.
Feeling confident, Yu Hua closed the book, packed his things and stood up. Seeing that Lin Wan was still studying English, he left without disturbing her.
…
Inside the dormitory.
The kerosene lamp burned slowly, releasing a dim light.
Yu Hua held the wire in one hand and a knife in the other, carefully peeling off the plastic skin to expose the copper core inside, and then wrapped the copper core around the positive electrode of the small inverter.
Surrounded by roommates, Liu Tao, Zhou Yuan, Ji Han, Cheng Youping and Cao Wei were all attentive, staring intently at Yu Hua and the portable lighting power supply equipment on the table, not daring to breathe.
After three days of waiting, today, taking advantage of the weekend, Ji Han finally came back with this set of lighting power supplies worth 20 yuan. After Yu Hua came back from the library, he was pulled by everyone to make lighting power supplies.
The two most valuable parts of the entire set of accessories are the battery, inverter, light bulbs, switches and wires, all of which are provided.
"Bring me a Phillips screwdriver." After connecting the positive terminal of the inverter, Yu Hua turned to connect the battery, peeled off the plastic skin to expose the communication, wrapped the positive terminal of the battery like a cat and a tiger, and shouted.
Liu Tao, who was the closest, hurriedly handed over the cross screwdriver. Yu Hua took it and tightened the battery screws. After solving the positive electrode and the negative electrode, he completed the equipment at the end of the device. Yu Hua then arranged the position of the light bulb and installed it in the middle of the dormitory.
After a while of clanking, the wire layout was completed and the 100W incandescent bulb was installed.
Everything is ready.
Yu Hua wiped his sweat, smiled at everyone, left a seat, and motioned to the light switch: "Who will be the first to turn on the light?"
The five roommates looked at each other, covered their right hands together, held the light switch together, and looked at Yu Hua.
Seeing this, Yu Hua smiled, stepped forward, turned on the inverter switch, adjusted it to the corresponding mode, and put his hands on the back of Cao Wei's hands.
"Da!" A crisp and short switch sound came out, and the next second, the incandescent light bulb installed at the top of the dormitory was powered on and activated, emitting a bright and dazzling light. The dormitory was bright, and there was no longer a dim scene like a kerosene lamp.
"Buzz!"
The sound of the inverter working stably came out.
"Haha, I'm waiting for the light!" Feeling the light from the incandescent lamp above his head and being in a bright environment, Liu Tao couldn't help being surprised and shouted loudly.
Light!
The light that symbolizes hope comes from the light of electric lamps.
The meaning of light is not trivial. To put it more simply, from now on they can read and study in their dormitories, no longer having to endure dim kerosene lamps, and no longer having to suffer the pain of myopia.
Speaking more broadly, the light of electric lights symbolizes civilization and progress, rather than backwardness and ignorance.
"I'm waiting for the light!" Zhou Yuan and the other four were extremely excited. Bathed in the light, they couldn't help but hug Yu Hua tightly.
Everyone was as happy as fools. Yu Hua was a little relieved and a little sad. The so-called portable lighting source in front of him actually had no technological content. The difficulty of research and development was just to assemble it. It would be ordinary in the future, even if it was a useless person.
Well-educated middle-aged people will accept it.
But in this era, this set of portable lighting sources has been labeled as "advanced", symbolizing civilization and technology.
Of course, it is not strictly correct to say that there is no technological content. After all, batteries, inverters and other components are all the crystallization of knowledge and the embodiment of technology.
"Quiet, everyone, keep quiet. Have you all learned what I did just now?" Yu Hua signaled everyone to be quiet. After everyone suppressed the excitement in their hearts, he asked.
Everyone looked at each other, nodded, and said in unison: "I've learned it." Just now, everyone in the city was observing Yu Hua's process of assembling the lighting source. The whole process was very simple and could be completed by just copying the cat.
After just one round of observation, everyone learned how to assemble this advanced portable lighting source.
Yu Hua nodded and said, "That's good. I have an idea. I don't know whether I should talk about it or not."
"Why should you be like this, classmate Yu Hua? We are classmates and sleep with each other. If you have any ideas, just feel free to do so." Liu Tao said bluntly.
The rest of the people nodded.
"I want to make a small fortune by relying on this portable lighting source." Feeling the attention from everyone, Yu Hua did not hide it and directly revealed the hidden thoughts in his heart.
make money.
Making a small fortune by relying on this portable lighting source that is so simple that it can be copied at will was Yu Hua's idea from the beginning, but he never mentioned it.
"What do I mean? Of course there is no problem. However, classmate Yu Hua, the cost of a set of portable lighting source components is 20 yuan. This is because of classmate Ji Han's family relationship. It is difficult for ordinary people to accept it. If you are rich and wealthy,
The noble family doesn't like it..." When Liu Tao heard Yu Hua's idea, he didn't object. He put himself in Yu Hua's shoes and thought about it. After thinking about it for a while, he couldn't help but frown slightly.
The price of a complete set of portable lighting sources is undoubtedly expensive. The cost alone is NT$20, not counting the electricity bill. The price is so expensive that ordinary people cannot afford it.
But they look down on people who are rich and noble. They live a luxurious life, and a chandelier can be worth hundreds of thousands of dollars.
If you can't succeed at a high level, you can't do it at a low level.
"I won't sell it to ordinary people, or to rich and noble people, I will only sell it to you." Yu Hua smiled slightly and responded.