"There are some things to say, some things to say, some things to say, and some things to say, and some things to say, "Langjie said this at the family dinner in the evening.

"Ajie, you've been second in the grade, and you've tried your best." Lan Jinhui said a fair word, and he said again: "From May 1, your salary will increase by 130 yuan."

"Uh, momo..." Lanjie said nothing and said nothing.

Teacher Lan sets the rule that Lan Jie will increase his salary by 10 yuan.

Ranger improved from thirteenth to second place, and the correct value of salary increase was 110 yuan.

How could Teacher Lan calculate such a simple math problem wrong?

Well, Teacher Lan drank a pound of sauce-flavored liquor. Although it was not as high as Teacher Lan, a pound of liquor also produced more or less alcohol.

If Teacher Fanlan eats two peanuts, he will not calculate the math problem wrong. Lanjie can only understand this way.

Lan Jinhui kneaded two peanuts and said, "Ajie, you celebrate your birthday in July, and you will get an extra 20 yuan. When you celebrate your birthday, you will buy a few gifts you like."

That's right. Teacher Lan, who moistens her throat with a pound of white wine, cannot calculate the math problem wrong. Lan Jie expressed his gratitude: "Oh, thank you dad."

“Not high mood?”

"Thank you dad!!!"

Ranger, who received the bonus and increased his salary, has a stronger belief in his belief. Learning is above everything else. Loving studying does not necessarily mean getting rich, and not loving studying will definitely mean being poor.

The next morning, Lanjie came to the classroom early, and the person who was earlier than him was Li Zihan.

"It's so early, Zihan."

Ranjie greeted Li Zihan enthusiastically. Zihan got the second place in the class (3) this time and ranked 20th in the whole grade (33). Zihan has made great progress. Zihan, who is mediocre but extremely diligent, is a representative of inspirational students.

Li Zihan responded: "Good morning, Langjie."

"Brother Hanzi is in a good mood." Lanjie was so moved. Li Zihan actually greeted him for the first time, "Good morning Lanjie".

Li Zihan took out his cell phone and said, "You can find out the WeChat QR code."

"Yeah!" Lanjie was even more moved. Zihan wanted to add friends with me.

The two of them added friends to each other, and the friendship further sublimated.

After more than three semesters of hard work, Lanjie finally became a friend of every classmate in the class.

If you become your WeChat friend, you can view your circle of friends.

Ranjie entered Li Zihan's circle of friends with great enthusiasm, and Zihan only showed the updates within three days.

Li Zihan has not updated anything in the past three days, and his circle of friends is empty, with only a ruthless dividing line.

At the same time, Li Zihan was also checking Lanjie's circle of friends. He turned around and asked, "On the 30th, do you want to go to the Sports City to participate in the long jump competition?"

"Yes, right."

“Are you sure to get a good ranking?”

“Yes, yes.”

"Langjie, actually, I'm fine on the 30th. I might go to the Sports City to watch the game. Should I book the tickets in advance or buy them on site?"

"Enter free with student ID." Ranger Xian was surprised. He said: "The long jump competition is boring. Zihan, would you really go to see me jump?"

"This track and field event is not just a long jump competition, right?"

"Run jump shot, everything."

"Since it's free, you can enter the venue at any time, let's talk about it later."

"Okay, Director Li is welcome to come to the site to guide the work."

As my academic performance improved, my popularity improved for no reason.

Ranger's popularity is already Nice. After he was promoted to the second strongest man in the grade, his popularity seems to have become even greater.

The first class in Class 2 and 3 was a physics experiment class, and the students moved to the laboratory building to do experiments.

Although the experimental class hours are much less than theoretical classes, Tang Xiaoyun attaches great importance to experimental classes.

Before doing the experiment, Tang Xiaoyun had a word: "If anyone fails to complete the experiment as required, then keep doing it until it passes."

This experimental class is operated separately by each student.

The experimental materials for each student are: two reading glasses, one thin convergence lens, one scissors, one screwdriver, one ruler, several cardboard shells, several translucent paper, and several coloring pens.

Tang Xiaoyun's requirement is to use these materials to assemble a simple Kepler telescope. It is known that the minimum resolution angle of the human eye is 3×10^-4rad, the diameter of the thin converging lens and the focal length are all 2cm. The length of the lens barrel is required to be 62cm, and after the telescope is assembled, it can distinguish two tiles 1mm spaced on the object surface 100 meters away.

The experiment required arrangements were clearly stated, and the students took action immediately.

This optical experiment is relatively simple for Ranger. Before assembling the telescope, he first needs to calculate the diameter of the objective lens that meets the conditions.

The eyepiece is a small and exquisite thin converging lens with a diameter and focal length of 2cm, which is a known condition.

The objective lens is reading glasses, with a total of two reading glasses, one large and one small.

The diameter and focal length of these two reading glasses can be measured with a ruler. What Langjie needs to do is to choose the right reading glasses.

Due to the diffraction effect of the objective lens, the minimum resolution angle δθt that the telescope can resolve is determined by the size of the objective lens, that is, δθt=1.22λ/d.

In the formula, d is the diameter of the objective lens, λ=550nm is the most sensitive yellow-green light wavelength of the human eye, and the minimum resolution angle is δθm1mm/100m=1×10^-5rad, so δθt≤δθm, and d=6.7cm is obtained.

Ranger quickly calculated 6.7cm in the draft, so he chose reading glasses with a diameter of 6.7cm.

"The first step to pass in this experiment is theoretical calculation. First calculate the correct diameter of the objective lens, and then choose the appropriate objective lens. Although the theoretical calculation part of this experiment is not difficult, this type of optical experiment changes rapidly, and as the known conditions change, the difficulty of the experiment will also change." Tang Xiaoyun walked back and forth, and she gave some tips while supervising the worker.

Ranger operates a screwdriver to remove the lenses of the reading glasses, lift the knife and fall, and the lenses and frames are smoothly separated.

Some students have extremely strong hands-on skills, while some students have extremely poor hands-on skills.

The routine operation of removing lenses is not difficult at all, but some students are in a hurry and cannot remove the lenses.

"Huang Yuhang, stop!" Tang Xiaoyun shouted sharply, her face gloomy.

Huang Yuhang had a lot of ideas. He didn't need a screwdriver at all. He removed the lenses with his bare hands, click!

There are all kinds of forests when the birds are big, Tang Xiaoyun stomped her feet irritably: "Huang Yuhang, is there anyone who dismantles the lens like this? I deliberately destroy the experimental props, 0 points! Not only 0 points, but also to lose money!"

Huang Yuhang was also very innocent: "Teacher Tang, the screwdriver is useless..."

Tang Xiaoyun angrily scolded: "Nonsense! Other students disassembled well with screwdrivers, but it won't work until you are here? Redisassemble it for me and use screwdrivers to disassemble it!"

Tang Xiaoyun was guarding Huang Yuhang one-on-one. She said angry and blamelessly: "Huang Yuhang, your ability to do things is so poor. Is it because I didn't teach you well, or are you born with a broken hand?"

"Teacher Tang, you taught very well. It was because I was deeply disabled and lowered the average line of our class..." Huang Yuhang apologized repeatedly. Under the guidance of Teacher Tang, he used the right tools and finally removed the lenses of the reading glasses through the correct method.
Chapter completed!