The self-heating rice is getting louder and louder. Don't turn your face to Jiang Yufan's mouth when Lezhi, "Why does this still have a sound?"

Jiang Yufan shook his head frantically, gesturing to him, "I don't know..."

Hu Xuan in the front seat turned around, raising her hand with a silent expression and drew a cross on her chest.

But Song Yu seemed to be isolated from the world, without any response, and even half of a mind map had been drawn on the blackboard. Behind him, the whole class laughed and performed a wonderful pantomime. The only accompaniment was the sound of self-heating rice, which was comparable to the increasingly exciting symphony in the golden hall.

Not only that, the experience is still in 4D, with a hot white mist wafting from Lezhishi's drawer, as well as the aroma of fish-flavored pork shreds.

I wanted to have a meal secretly, but now it's better. The whole class, including Song Yu, who leads the class, know that he is cooking.

Le Zhishi gave up completely, and he had already been reprimanded and ordered out of the classroom in his mind, and then squatted down in the corridor to have a sad meal.

He feels that he is a very experienced person now, and he can answer the question "What is the experience of social death" anonymously.

Finally, after ten long minutes passed, Song Yu turned around blankly and put the half of chalk that hadn't been used up on the table, "This is what I want to say next."

The sound of self-heating rice began to become like a deflated and deflated balloon, and the sound became more and more lingering, just like Lezhishi's head hanging on the table at this time.

"The first part is to find your weakest link. You all understand the barrel effect." Song Yu said down, but unsurprisingly, he walked down the stage.

Rows of students under the stage hurriedly put away their mobile phones, and the student at the front turned to look at Le Zhishi with the mentality of watching a theater.

According to the rumor, the person who bullied his younger brother came to lead the class, so that he was caught stealing food in class. If you don't give a severe lesson, you can't just think about it.

"Systematic sorting of wrong questions is an effective way. Making mistakes is not terrible. Everyone will make mistakes. It is terrible that many mistakes will be repeated and eventually lead to loss of points. So what you should do is to reduce the frequency of the same mistake."

In words, he had already walked to the side of Lezhishi, his slender hands seemingly inadvertently propped on his desk.

He speaks steadily and logically. From the topic of sorting out wrong questions to the skills of scoring multiple-choice questions in mathematics, such as the combination of figures and the method of substitution, Coke Zhishi is an ostrich, except for his own heartbeat. , I can't hear anything.

Song Yu seemed to torture him deliberately, and stood by his side and said, not going anywhere.

"...This is the part of multiple-choice questions. Now you practice the multiple-choice skills just mentioned with the questions at hand, for ten minutes." After speaking, Song Yu finally lowered his head and looked at Le Zhishi who had been pretending to be dead. , The bent knuckles tapped the tabletop lightly.

Le Zhishi raised his head pitifully, with an expression that I really knew I was wrong, and honestly took out the self-heating rice box hidden in the drawer.

Song Yu raised his eyebrows in a low voice, "Is it sweet?"

Hearing this sentence, the surrounding students couldn't help but laugh.

"It's okay." Le Zhishi replied very honestly, then added in a low voice, "It's a bit fragrant."

Jiang Yufan is a loyal person. Seeing that Song Yu was embarrassed, he immediately explained to him, "Senior, I bought this. I bought it wrong. Blame me. I can write a review."

Seeing that he wanted to take responsibility, he immediately spoke when he was happy to know, "No, I want to eat it myself."

Zhang Chen didn't think it was too much to be crowded, "Senior, I can attest that it was eaten when Lezhi. They had been sneaking in for a long time before, and they just wanted to eat self-heating rice during the evening self-study."

Jiang Yufan was very angry, "Are you qualified to say it? It's as if you haven't eaten takeaways during your own study at night. And he didn't plan to eat in the classroom."

The two quarreled, and Song Yu's eyes swept over the students who were laughing. Everyone seemed to be looking forward to his punishment. In the end, he opened his mouth blankly.

"Take this opportunity to tell you the principle of self-heating rice."

Zhang Chen's face was unbelievable, which was completely different from the direction he wanted to file a penalty complaint against Sanlian.

Ignoring the whispers of the surrounding students, Song Yu picked up the lunch box on the table and said, "Look here."

"The bottom layer of the self-heating rice box contains a heating package, which contains chemical agents such as quicklime, sodium carbonate, and aluminum-magnesium mixture. Quicklime is calcium oxide. It reacts with water to form calcium hydroxide and releases a lot of heat. Carbonic acid Sodium often plays an auxiliary role in it, and aluminum-magnesium powder can also release heat through oxidation. So when we inject water, the heating pack will work to automatically heat the food."

He bowed his head and met Lezhishi's surprised eyes, and continued: "However, this kind of self-heating fast food may also explode, and the freshness of the food is not enough. It is not recommended to eat it frequently."

After finishing speaking, Song Yu put down the lunch box and pointed back to the blackboard, "I have written several related reaction equations in the lower right corner of the blackboard. Those who are interested can take a look."

Lezhishi looked at the equation on the blackboard. It turned out that at that time he already knew what had happened and wrote it calmly.

At first, everyone just thought it was funny and wanted to see the excitement, but I didn't expect the mutation chemistry class of the social death incident, and it was still a bit embarrassing. What's amazing is that part of it reflects that they have learned it, but they have never connected to life. Such a comparison gives a kind of magical feeling.

"Combining with the example just now," Song Yu leaned at Lezhishi's desk, "you should never forget that calcium oxide is an exothermic reaction when it meets water."

Everyone laughed at the same time, but Zhang Chen was obviously still unwilling. He raised his hand with a stern expression on his face, "Senior, then why is there a sound? It's too funny."

This obviously wants to bring everyone's attention back to the time when the self-heated rice was sneered.

Song Yu leaned at the table and did not answer directly, but looked at other students, "You should have done chemistry experiments. Can anyone tell me which chemistry experiments you have done have special sounds?"

A girl whispered, "Sodium and water..."

Song Yu nodded affirmatively to her, "This example is very classic, and many chemical reactions make sounds." He deliberately glanced at Zhang Chen, who had deliberately asked the question earlier, "Nothing to fuss about."

Zhang Chen couldn't hold her face quickly, and obviously felt a trace of sarcasm in the other's cold tone.

"Except for the reaction itself, a lot of water vapor will be generated during the exothermic process, and sound will also be produced under collision. This process contains many reactions like galvanic batteries, which you have not learned so far."

Song Yu lowered his head and glanced at him, "I believe... if Le Zhishi's classmates understood the principle behind this from the beginning, they would not choose to heat self-heating rice in a quiet environment."

Le Zhishi classmate.

This title sounds weird when Lezhi, but somehow it evokes a hint of joy.

Although Song Yu still had a cold expression, it didn't mean to blame. The clear sentences are all about popularizing chemistry knowledge, but everyone can hear the hidden excuses.

Le Zhishi thought, now his anonymous answer can be updated in real time at the bottom of the sentence "I'm alive again!" No, he can even cancel anonymity.

As he was stunned, a wide palm fell on his head and rubbed his fluffy and soft hair, which was short and light. He didn't react, he only felt the hand leave the top of his head, but left a word.

"If you don't eat it, it will be cold."

The killing came suddenly, and the students around were a little surprised.

The so-called rumors of poor brotherhood were self-defeating under Song Yu's extremely rare close contact.

Lezhi didn't lift his head, "I'm going out to eat."

After he finished speaking, he took the lunch box and walked out, a bit on the same foot.

The bathroom was on the right side of the stairs, next to the bathroom, and when Lezhi saw no one, he slipped in. The taste of convenience food is ordinary, the rice is hard, and the dishes are a bit too salty.

He chewed and was in a daze. After swallowing, he raised his hand fascinatedly, touched the top of his head, bowed his head and took another big mouthful.

I didn't feel hungry until I was hungry. What happened just now happened again. I couldn't eat well when I knew it. I was thinking about what Jiang Yufan said he wanted to taste. He didn't leave after eating. But the little Jiang Yufan has experienced too much and can't remember anything. He waited for five minutes and didn't show up.

Song Yu is still in the class. Lezhishi didn't want the ink to be too long, so he cleaned up and went back to the classroom. When he arrived at the door, Song Yu was standing on the podium speaking the English review plan. He stood at the door and shouted a report softly, but didn't enter directly.

Hearing the sound, Song Yu nodded to him, and then continued speaking if nothing happened.

Le Zhishi quietly returned to the position and listened to the lecture with other students. After the entire class, Song Yu, who didn't bring any materials, only spent ten minutes sorting out the context of the mind map, and then led everyone through it with clear thoughts. The level of ease even surpassed many teachers.

"Time is limited, so let's talk about it." Song Yu stood sideways, looked down at his watch, and was about to start the first night of self-study.

"Lezhishi."

Hearing his name was called, Lezhi was stunned for a moment, and quickly raised his head to look at his brother.

Song Yu nodded his chin toward the blackboard, "wipe the blackboard."

Le Zhishi immediately nodded obediently, "Hmm." He said that he was about to stand up.

Since childhood, Lezhishi’s most feared thing was that Song Yu ignored him, especially after he did something wrong, but if Song Yu taught him a lesson or gave him something similar to punishment, it would mean that he was not angry. .

Song Yu couldn't speak when he was really angry.

They all know each other enough.

"Don't wipe it," the girl taking notes looked up. She didn't listen to much during the explanation before, and now she rushed to copy the blackboard, "I haven't finished copying yet." Other people also followed, Le Zhishi was in a dilemma.

Song Yu glanced faintly, "Since the phones you bring can chat, you should also be able to take pictures."

Everyone was choked by this sentence, especially those people who were still chatting gossip and watching jokes in the group just now.

The school bell rang and Song Yu left the classroom. Le Zhishi did what he said to wipe the blackboard. Jiang Yufan spoke of loyalty and took another blackboard eraser to accompany him, "Is that delicious meal?"

"It's okay." Lezhishi looked at him, "I waited for you for five minutes, and you didn't go."

"You've been waiting for me for a long time. I said why it took so long. I forgot." Jiang Yufan rolled up his sleeves, "Zhang Chen's stupid fork still stuns you, asking if you are too embarrassed to come back, so angry. If I can't chase, I will vent my anger at others."

Lezhishi waved his arms and worked hard to wipe the blackboard. He didn't care much about what he said when he was away. "He also has a mouth addiction for the past two days. If the person I like likes others, I am definitely not happy. "The hand holding the eraser suddenly stopped, and Lezhishi's gaze stayed on the lines of equations in the corner.

This was the last unfinished task in the clearing task that Song Yu assigned to him.

"Is your phone on you?" He turned his head to look at Jiang Yufan who was photographing dust.

"Yes, what's the matter." Jiang Yufan directly took it out and handed it to him, "You only remembered to shoot now, it's all gone."

Le Zhishi didn't speak, and used his mobile phone to take pictures of these lines of equations in the lower right corner.

"Thank you, send me this."