Back in 1978, I was admitted to Northwestern Polytechnical University.

Chapter 21 Does being ranked first mean you don't have to come to class?

Tang Changhong gave Yang Wei a satisfied look. "You've learned your lesson, kid. You're not the same clueless kid who used to call me 'uncle' anymore."

We shouldn't criticize Qin Liang for skipping class for a week, as that might hurt his self-esteem. Geniuses usually have very strong self-esteem. It would be better to ask him for help. If he doesn't know the answer, we can patiently persuade him, and everything will fall into place naturally.

The dormitory supervisor's footsteps could be heard outside, urging everyone to go to sleep. It's not good to use the corridor lights for sleeping. Without enough sleep, how can you have the energy to face the intense study the next day?

However, those in the dormitory who were using flashlights could only be ignored.

Zhang Zhigang, who was on the upper bunk, turned on his flashlight and shone it on Yang Wei's open textbook, which was covered with dense English letters.

This is actually an English textbook?
Great! The English textbook is good. Let Qin Liang know that we have been studying English for a week. Everyone has learned a lot of words, and with the help of the dictionary, we can already understand the textbook!
Wait, no, there's a GRE symbol next to this question. If I remember correctly... this is a postgraduate entrance exam question!
This English advanced mathematics textbook is quite good, and it also comes with practice questions, ranging from simple to difficult, with a few postgraduate entrance exam questions at the end!
Teacher Zhao said that these questions marked with the GRE logo are optional and not required to be mastered. They won't be on the exam. Since everyone's abilities are limited, they didn't take them seriously. Unexpectedly, Yang Wei, who is second in the class, is actually pondering these questions!
Okay, I overestimated Yang Wei. He didn't play any tricks; he genuinely didn't know the answer and wanted to ask Qin Liang for advice.

You've been studying diligently for a week and still can't do it. Qin Liang, who skipped class for a week, is asking you this question. That's asking too much!
Qin Liang had no idea about the intricacies involved. He was very sleepy, his eyelids drooping, and after only glancing at it, he said, "The answer is one-negative half."

Yang Wei quickly flipped to the back; the last few pages contained the answer key. As long as he found the correct question number, the result would be correct. But when he turned to the right page, it clearly stated "-1/2". Damn it, what happened to the answer key? There were only answers, how could he use it as a reference? Where was the process? Where was the process?
"Qin Liang, you're amazing!" Zhang Zhigang, shining his flashlight, saw it most clearly and was instantly impressed. He was indeed number one; he could get first place without even studying.

"Qin Liang, could you explain this to me? Look, I've spent a whole page working on this, but I still can't figure it out..." Yang Wei humbly asked for help.

Qin Liang glanced at it.

lim (X->0 is below lim), followed by a fraction, the top part is the square root of 1+2sinx, then -X-1, and the denominator is xln(1+x).
In advanced mathematics, the first thing to learn is how to find limits. In later generations, this part of the curriculum has been moved to high school.

Of course, the questions can be made very difficult, even like the postgraduate entrance exam questions, just like the one we're talking about now.

"There's a trick to finding the limit of a formula as X approaches 0," Qin Liang said. "It's very difficult to find the limit of such complex trigonometric function formulas using normal methods. In this case, we can use some formulas to directly substitute, for example, sinx can be replaced with X, tanx can also be replaced with X... This method is called equivalent infinitesimal substitution. Try this method, I'm sleepy..."

After saying that, Qin Liang climbed into bed.

What?! Nobody remembered?! Qin Liang, would you like to say it again?
Tang Changhong and the others were all staring intently at Qin Liang when they heard that familiar snoring sound, along with a rustling sound.

Everyone looked down and saw that Yang Wei had already started calculating rapidly. A minute later, he exclaimed excitedly, "Qin Liang, this really works!"

Demon!
The top student in the class doesn't need to learn; he can figure out how to do it just by glancing at it, as if he's already learned it beforehand. The second-best student in the class has a photographic memory; he can remember something after hearing it just once!
Seeing the complicated looks on everyone's faces, Yang Wei realized what was going on: "Wait here, I'm going to write down all ten of those equivalent infinitesimal substitutions that Qin Liang just mentioned..."

A new week has begun!

After morning reading, the smell of steamed buns wafted through the classroom again. To save time, at Tang Changhong's suggestion, the class decided to get lunch together. Since it was always the same steamed buns and pickled vegetables in the morning, only two people needed to go, and the rest of the students could continue studying in the classroom.

Time is tight! I can continue memorizing vocabulary while eating steamed buns.

"Yang Wei, who's number one in your dorm?" Zhao Xiaoxia couldn't help but ask again.

"That's right, he hasn't been to class for a week. If he doesn't study properly right after the start of the semester, how will he keep up with us?" "I think this is clearly arrogance!"

Yang Wei looked at the person who spoke: "Zhang Yong, you're wrong about that. Last night I..."

He wanted to tell Zhang Yong what happened last night, but Zhang Yong interrupted him.

“Yang Wei, what did I do wrong? How can he learn all this knowledge if he doesn’t come to class? Although we’ve only been in class for a week, everyone has put in the same effort as the past month! With so many courses and such advanced theories, even if Qin Liang was once the top student in the class, he’ll fall behind now!”

“That’s right! You’re all in the same dorm, and you didn’t even try to help him…” Zhao Zhijian, Zhang Yong’s dormmate, chimed in.

"No, no, you've all misunderstood him. Qin Liang is very capable. Last night..."

"What are you trying to say? He sleeps in his dorm during the day and studies at night? This kind of reversed day-night habit is not good. Besides, self-study is never as good as being taught by a teacher. Even if Qin Liang is number one, can he really study on his own without a teacher?"

“Zhang Yong, stop talking. What exactly happened last night?” Zhao Xiaoxia pressed for details.

"last night……"

Ding-a-ling... Just then, the school bell rang.

Many universities don't have bells; class times are managed by the teachers. However, some classes inevitably run overtime, so bells are still needed to remind students to start class and teachers to end get out of class.

Everyone quickly returned to their seats and looked towards the door, looking somewhat puzzled.

Teacher Zhao usually arrives ten minutes or more early, why is she late today?
One minute, two minutes, three minutes...

"Class, please preview the textbook first. I'll go ask around the office building." Zhao Xiaoxia stood up.

From the very first day she asked her senior to come and help teach English, Zhao Xiaoxia has gradually become everyone's class monitor. Today, since the teacher didn't come, she decided to take on the task herself.

Bang! Just then, the door opened.

The teacher is here!

Wearing a cool short-sleeved shirt and gray trousers, she looks very young. If it's not Teacher Zhao, could it be another teacher?

When everyone looked at that face, some people were confused. Who was this? He looked familiar, but also...

Zhao Xiaoxia was immediately overjoyed: "Qin Liang, you've finally arrived! You've missed a week of classes, you can't miss any more in the future..."

(End of this chapter)