When Zhao Bai'an got up that day, it was already just past noon and approaching the afternoon, but the rainy weather had already passed, and with her good mood of giving the gift to Ah Mu, the dark clouds also dissipated.

By the time I walked around the campus again the next day, winter was getting closer and closer to everyone, and the surrounding environment was changing every day, and it was all clear that it was all visible.

Autumn is still lingering to seize the last opportunity. Fallen leaves are scattered all over the ground, Zhao Bai'an is about to go to the classroom to go to class, looking at the fallen leaves that have not been swept all over the ground, she can't help but want to chant a few words, but this is not her style. Perhaps it would be more appropriate for Huang Han to do this.

Thinking that the golden autumn and November are also named after this, there are also a few fruit trees planted in the small garden of Haichuan, Zhao Baian looked at the fruit trees not far away and the fruit was already heavy and wanted to sink, and he couldn't help but want to pick a few along the way. It's just that she can guarantee that it's very sour! Don't ask her how she knows, it's all bitter tears.

When walking alone on the road, he always likes to diverge his thinking, and Zhao Bai'an once again thought of his appearance when chatting with Ah Mu, and couldn't help laughing.

Ah Mo actually had a smile on his face when he got the poster given to him by Zhao Bai'an, but it was fleeting, and it was not a small skill to be pressed back by it in an instant. I don't know if it hung the poster at home, just like she hung it in her bedroom. But even if you ask, you will definitely be denied.

"I obviously like it very much, but I insist on making it look very ordinary, it's really arrogant!" Zhao Bai'an laughed while thinking and whispered something by the way, completely unaware that Chen Yudi appeared behind her.

"Hey, Bai An! What a coincidence. ”

Zhao Bai'an was too immersed in thinking about Ah Mu's previous reaction, causing her to shudder after hearing Chen Yudi's voice.

She calmed down for a while, turned her head a little slowly, and then spoke: "Magician...... classmate"

"Ah, the weather isn't particularly cold now, what are you shivering?" He smiled and joked about Zhao Bai'an, it seems that he is in a good mood today.

After the last escape room activity of the Reasoning Society, the relationship between the two of them has actually become much closer. Compared with the beginning, he seems to be less restrained and shy towards Zhao Bai'an, and he always chats after daily meetings, and shares interesting things online through his mobile phone.

"What are you thinking?" He watched Zhao Bai'an's thinking diverge again, so he pulled her back again.

"Huh? Chen Yudi, hello! Maybe it's because the reaction just now hasn't completely disappeared, Zhao Baian was still a little stunned, and even called out his name directly.

"Wow, classmate Zhao Bai'an, what's wrong with you today?" Chen Yudi faced Zhao Bai'an's abnormality, and even said interjections that had never appeared from his mouth.

This was really embarrassing, and Zhao Baian could feel that her face was starting to burn.

When she didn't know what to say to him, she remembered that the purpose of this trip was the college general education class that the two of them were taking together: "The next physics class seems to be about to start, so let's go quickly!" ”

After saying this, Zhao Baian didn't wait for Chen Yudi to respond to her, so he pulled him forward in a hurry.

"Ah......h

He shouted behind Zhao Bai'an, but then he didn't say anything, and Zhao Bai'an didn't look back.

She realized she was pulling him halfway through and immediately turned around and let go. Zhao Bai'an saw Chen Yudi's ears red from congestion again, presumably the low shout just now was because of this. The two of them looked at each other awkwardly for a moment, then walked to the physics classroom one after the other.

The two of them didn't arrive too late, most of the students in the classroom had already arrived, and almost 70% of the seats were full, if not all.

Before the physics professor came, the two of them sat down in the same position they used to sit in as usual, one on the left and one on the right.

I don't know if it's because the two of them always come at a particularly good time, and this double seat has always been like it's reserved for the two of them, and it's often empty. Since singing K on National Day, Zhao Baian and Chen Yudi will sit together in class every time.

In fact, the seat of the university is not like that of junior high and high school, and the seat of the university class is decided by yourself, as long as you come early, you can sit where you want. The choice depends on your own wishes and the time you walk into the classroom.

Therefore, in college, there are always a few students who come to the classroom early to grab a seat.

Although Zhao Baian originally had such an idea, he insisted for a few days and found that those classmates who were really working hard to grab a good seat. It's better for her to be casual. Just like now, although the time of her own visit is different every time, isn't this position always vacant for her!

After the two sat in their seats, Chen Yudi took out his notes, Zhao Baian secretly glanced at his notebook, and what he saw was a dense collection of knowledge points, but that page was not completely used up, and there was still about half a page of blank waiting for him to fill in.

Seeing Zhao Bai'an's scattered black letters and large blank spaces in her notebook, she couldn't help but feel ashamed. It's not that she doesn't take her classes seriously, it's just that she prefers to memorize only a few pictures or bullet points. If she completely reproduced what the professor wrote on the board, she would be less efficient at listening to the class. But I have to say that Zhao Bai'an's seriousness is naturally not as serious as Chen Yudi's.

Classes at Haichuan University are basically three hours in a row, and there will be a 10-minute break at most. Zhao Bai'an is always very serious in the first hour of each time, and then after a break, he will start to wander infinitely. On the other hand, Chen Yudi, every time Zhao Baian observed him, he looked in the direction of the professor intently. It really made her embarrassed.

The professor in this class talks about a series of knowledge about photons and kinetic energy, and at the beginning, I didn't feel particularly difficult, it was nothing more than the knowledge of photoelectric effect and wave-particle duality, which was similar to what Zhao Bai'an learned in high school. However, as soon as I let my guard down, I lowered my head and played with my phone for a while, and when I raised my head again, I almost wanted to make people smash the table and leave the field.

No, no, try to understand. It's only been a short while, and it's not too far off.

"The Compton wavelength is the length dimension of the system when quantum effects begin to become important, and the greater the particle mass, the shorter the Compton wavelength. The Schwarzschild radius is the radius of the sphere in which all of the mass of a particle becomes a black hole, and the heavier the particle, the larger the Schwarzschild radius. When the Compton wavelength of the particle is approximately equal to the Schwarzschild radius, the mass of the particle is approximately Planck's mass, and the motion behavior of the particle is strongly influenced by quantum gravity......"

No, no, Zhao Bai'an, you have to come on! Zhao Baian silently shouted to himself.

Although it seems that the more I listen, the more sleepy I become.

"The probability of the occurrence of the photoelectric effect is measured by the cross-section of the interaction. The parameters of the cross-section are the atomic order Z of the target atom and the photon energy. For the photon energy E is greater than the maximum atomic binding energy, the K electron cross-section σ can be roughly estimated as follows......"

Hey, forget it. Wait until after class to go back and read a book. Zhao Baian comforted himself in his heart.

She cast a helpless look at Chen Yudi, although Zhao Bai'an knew that he must be full of eyes only the figure of the professor.

Sure enough, he was looking up and down for a while, as if he would miss something important if he didn't pay attention to it.

Huh? He actually felt Zhao Bai'an's eyes and looked at her.

At this time, Zhao Bai'an was still in a state of being extremely confused when she wanted to complain, and she was stunned for a moment when she saw Chen Yudi's abnormal behavior. The moment the four eyes met, Zhao Bai'an's originally messy head was instantly emptied.

Chen Yudi smiled at Zhao Bai'an instead, opened the coil-shaped notebook, took out a page and handed it to her, and said in a low voice: "You were distracted just now, the main point of the professor's lecture is here, you take a look first, otherwise you will definitely not understand the rest of the book." ”

After that, he went back to listen to the lecture again, if it weren't for Zhao Bai'an just seeing the action of him picking up the pen again and the piece of paper he was holding in his hand, all this would have become so unreal.

Zhao Bai'an looked down at Chen Yudi's notes, which were typical of boys' handwriting, the font was too large, the pen was not too convergent, and the glyph was not very well mastered, and it was generally flat and wide. Although the words are not very good-looking, they are very neat, and they are clearly divided one word at a time.

The words of the professor's lecture continued to reach Zhao Bai'an's ears, but her attention was focused on Chen Yudi's notebook. The overall record is very planned, and he sometimes writes his own understanding in the difficult places. This made Zhao Baian quickly make up for the content of the previous distraction.