Bai Yueguang came back with the system

Rose branches climb all over the wall on the north side of the music activity room, swaying in the wind along the fence, with deep and shallow pink waterfalls, clusters of flowers, and lingering fragrance.

Several Yulin girls with exquisite faces were standing on the sidewalk under the flower wall, letting their friends take photos. Their faces were filled with happy smiles.

Occasionally, there are students who peek out of the floor-to-ceiling windows out of curiosity. The most beautiful people from Yulin Middle School are inside.

However, they stopped for a while outside the music activity room and then fled with frowns on their faces.

Yu Yanchu was in a irritable mood, but his beautiful face was not visible. He was pulling the cello strings in his hand with his head lowered.

The piece the four of them chose to perform was "susannata" by the German Quadro Nuevo Quartet. The style of this ensemble is warm, lively and bohemian, like dancing a passionate flamenco with friends or a provocative tango with a lover.

The gentle and agile piano, the deep and mellow cello, the full and melodious saxophone, and the ups and downs of the drums.

A beautiful and smooth ensemble requires coordination between different instruments and appropriate playing order, pitch and tempo.

Yu Yanchu couldn't figure out why the four of them sounded like four dragons. How could they turn into insects once they met?

Really──

It's a mess!

Horrible!

Before it was over, Yu Yanchu put down the bow in his hand.

The three handsome young men sat in front of their respective instruments, frowning and still playing. When they heard the sound of the cello stop, Lin Mingjia and Ji Heng also stopped.

Only Ning Zhuoyi was still playing the saxophone intoxicatedly.

After a while, he also reacted and stopped in confusion.

"Why don't you continue?"

Yu Yanchu raised her pretty face like a hibiscus with a cold expression. She stood up and put the cello in order.

"I still have a lot to do and this ensemble is a complete waste of time."

After Yu Yanchu left, their voices complaining to each other could still be heard from the music activity room——

"Ning Zhuoyi, are you playing the saxophone or the suona?"

"Ji Heng, I've tolerated you for a long time, and you play the drums as if you were on the battlefield!"

"Are you embarrassed to accuse me? The full and melodious saxophone makes you feel so passionate. Who are you courting?"

"Haha, I think you want to be beaten again?!"

The intense piano sound suddenly sounded, and the handsome young man played Maxim's "Flight of the Bumblebee" quickly and passionately.

"Ning Zhuoyi, do you think you can do it again? Since you were a child, when have you not been pushed to the ground and beaten by me?"

"Oh, you are so amazing. You wet the bed at the age of three, you are so awesome!"

"Are you going to mention your childhood? Then I can talk to you for three days and three nights. I wonder who chased the dog and knocked off his front teeth? He leaked like an old lady."

The two people were quarreling faster and faster, accompanied by the rapid piano sound. As the last note of the piano fell, Ji Heng and Ning Zhuoyi also stopped breathlessly and had a temporary truce.

Lin Mingjia looked helplessly at the two childish elementary school chickens, "If you keep doing this, I'm not sure if Yu Yanchu will quit this performance."

Ji Heng frowned, his face gloomy, and he was very dissatisfied with Ning Zhuo when he mentioned that he wet the bed when he was a child. "Yu Yanchu is participating in a mathematics competition recently. I think she is so busy that her eyes are a little dark."

Ning Zhuoyi was not afraid of Ji Heng at all, but he was afraid that Yu Yanchu would be unhappy. He thought of Yu Yanchu's cold expression just now and felt a little uneasy.

"Let's practice more in private first, and then find Xiaochu to join us."

-

The next day, there was a break between classes.

On the playground, hundreds of Yulin students in uniforms were dancing between classes. Accompanied by the music BGM of "Calorie", several boys in the back row were twisting their bodies crazily, giving off the feeling of Northern Shaanxi Yangko.

When Principal Ning returned from an inspection tour of a public middle school, he introduced a recess exercise system, accompanied by the most popular music at the moment.

At first, the students in Yulin were very resistant to recess exercises, but gradually they started to dance with joy and joy——

Some people turned around to peek at their crushes, some dressed up beautifully to attract others' attention, and some took advantage of the recess exercises to go crazy. It was really lively.

The breeze blew her hair, revealing the girl's face that was as bright as the bright moon.

Yu Yanchu ignored the bright and dark gazes around him and stretched his slender limbs to follow the music. His white calves were wrapped in dark blue calf socks.

A boy suddenly ran towards her, "Classmate Yu, Teacher Qiu calls you over."

He saw Yu Yanchu stop, her clear and bright eyes looking at him intently, and suddenly became stammering, "In... in front of the team."

The boy's face turned red. After Yu Yanchu left, he took out his mobile phone and secretly took a picture of Yu Yanchu's back and wrote: Family members, who understands? When Poppy looked at you, you were completely stunned and speechless.

……

"Then question 10 has nothing to do with this."

"It was originally agreed that question 10 would not have an equal sign. What I meant was..."

"That can only exist if it is greater than 0."

"What he means is that there is a single decreasing interval, or there is a single increasing interval. Why is there no equal sign?"

Several teachers of the senior high school mathematics group were having a quarrel in front of the playground due to disagreements.

Master Qiu was so anxious that he simply squatted down with his hip-covering skirt and gestured directly on the ground, "Existence must be greater than or equal to him."

Several teachers stood around with suspicious looks on their faces.

Yu Yanchu came over at this time, "Teacher Qiu, are you looking for me?"

Mrs. Qiu stood up when she saw her favorite student coming, "Yu Yanchu, did you bring the parameter range for question 10 of the monthly exam, did you bring the equal sign? Tell a few teachers about your ideas."

"Well," Yu Yanchu thought about it, "whether or not it has an equal sign is related to the sufficient and necessary conditions for derivation and monotonicity. When a monotonically increasing or decreasing interval is given, the derivation must have an equal sign; for monotonic increasing and decreasing When there is an interval, the derivation does not need to include an equal sign; when there is a monotonically increasing or decreasing interval within a certain interval, the derivation does not need to include an equal sign."

"I didn't take it with me when I did the math. When I finally verified it, if the conditions were met, an equal sign was added to the process."

Several teachers nodded after hearing this, "Whether or not to include the equal sign is a mistake. This idea is feasible."

……

The post posted by the boy who helped Yu Yanchu just now was picked up by the students in Yulin, and they kept replying below.

When he turned on his phone again, he thought for a moment that he was on fire.

The comments below are all kinds of weird──

"Take my dear wife away."

"Poppy Poppins went over to discuss the topics for this monthly exam with the math teachers."

"I listened to it when I was passing by. I really like the feeling of a large amount of knowledge passing through my smooth cerebral cortex without leaving a trace."

"Please tell me upstairs that you don't understand."

"A poppy needs good looks, good IQ, good family background, and good love, and I will be her boyfriend. Dog head.jpg"

"The smell upstairs is shameless. Do you know that my wife Poppy coaxed me for a long time because of your words?"

"Yu Yanchu is also good at games. Last time I saw she had three national uniform standards."