"Didi, click!"

Cheng Yun opened the door and walked into the room, looked back again, and found that there was a place at the bottom of the door that was stained with dust, it should be that someone accidentally kicked the door when they entered and exited in the past two days.

Cheng Yun shook his head and continued to walk inside.

But after taking a step, he looked back again.

The entire door had been wiped clean by the goddess Liu, and it was as bright as new, except for that one with gray traces, which looked too conspicuous.

Cheng Yun frowned, couldn't help but walk back again, squatted down and wiped the piece of dust clean with his hands.

When you look at it again, it's much more pleasing to the eye!

Xiao Lori, who was sitting on the sofa, stared at his movements without blinking, while Cheng Yan, who was facing away from him, seemed to have no feelings, still giving a serious lecture, and passing the time by transferring her 'difficulty' to Xiao Lori.

Cheng Yun stood up, but stopped, he looked straight at the scene in front of him, and the corners of his mouth couldn't help but hook up a gentle smile.

"Geometric ideas are the most important class of ideas in mathematics!"

"For many branches of mathematics, you don't think that if you don't need them in your daily life, you won't study them seriously. In fact, mathematics is a very, very great subject, and if you want to be a great king of snow, you have to study great subjects. ”

"Compared with other branches, maybe you will use less geometry in your life in the future, unless you are involved in a special industry in the future, such as the construction industry, little Lori, you probably don't want to be an architect in the future, right?"

"Huh?"

"I knew you didn't want to!"

"But what we have to accept is geometric thinking! When you learn geometry, it will still affect you years later, when you have forgotten how to prove that one angle equals another—whether you are logical enough, whether you are clear enough to see things, whether you can communicate with others more easily to make people understand what you mean, and so on...... In short, it has become a part of your whole being, an indelible imprint of your soul. ”

"So what do we need to learn first...... Plane geometry!Hmm, little Lori, what are you looking at?" Cheng Yan turned around and saw Cheng Yun at a glance.

At this time, Cheng Yun's smile was brighter than before, he felt that Cheng Yan, who was teaching seriously in the picture just now, and Xiao Lori, who was obviously deserting, were really funny, especially Cheng Yan's last self-question, which was very similar to the teachers he had met, but her teaching object was a cat, which was too funny.

"What are you laughing at?" Cheng Yan suddenly asked seriously.

"I just thought it was funny hahaha......"

"......" Cheng Yan frowned, "Are you here to cook?" or are the guests coming soon?"

"Oh yes, yes, the guest is ...... right away It's here!"

"Then what are you doing, hurry up and pick him up!" Cheng Yan stood up suddenly, and at the same time she saw that little Lori also hurriedly waved her paws, and her junior high school math textbook slammed shut, as if it couldn't wait for it.

"If it doesn't exist, it's good to give him some buffer time. ”

Cheng Yun said, suddenly frowned slightly, then snapped his fingers, and in the next second, two people and one beast appeared in the node space.

"And snap your fingers......" Cheng Yan tugged at the corners of his mouth.

"Shh~~"

Cheng Yun motioned for her to be quieter and looked ahead.

Needless to say, Cheng Yan had already paid all his attention to the front after complaining.

I saw that there was a black spot about 100 meters ahead, and I couldn't see it clearly because the light in the node space was too dark, Cheng Yan had tried hard to open his eyes wide, but he still couldn't see clearly. I could only vaguely see that it was a large lump, with slight movement, and it seemed to be lying on the ground.

That's about the length of a standard playing field.

"It's ......"

She didn't act rashly, but turned her head to look at Cheng Yun inquiringly.

Little Lori replied to her: "Woo woo......"

Cheng Yun also said: "That's a person, an old man." ”

"Old man?" Cheng Yan was still curious.

"Well, let's go over and have a look. ”

As soon as Cheng Yun finished speaking, they had already appeared beside the space-time visitor.

Cheng Yan's eyes widened suddenly.

The first thing that caught her eye was a motorcycle that fell to the ground, the motorcycle was relatively old-fashioned, a bit of Harley, covered with dust, with two side boxes and a tail box at the back, and a lot of things tied to it, and the load was very large.

The big lump she had just seen, almost all of it was from this motorcycle.

Then there was a back squatting in front of the motorcycle.

Dressed in a heavy dark motorcycle suit, with a rickety figure, the helmet was placed next to him, and his sparse white hair showed his advanced age. He was carrying a wrench away on a motorcycle, and it seemed that something was wrong with the car.

All this was different from all the pictures Cheng Yan had imagined, but she was still curious.

Suddenly, Cheng Yun snapped his fingers again.

"Smack!"

The world suddenly brightened, and every inch of space was filled with a uniform white light.

"Ahh

The old man was startled, and let out a sudden exclamation, then turned to look at them, and in the process his weight was unsteady and he sat down on the ground.

It was a very old face, full of the vicissitudes of time, even much older than the old master.

The old man faced them like this, his cloudy pupils dilated, and he said tremblingly: "¥#......%#"

"Forgot. ”

Cheng Yun hurriedly summoned the crystal ball, but he could also guess what the old man was talking about just now, after being a doorman for so long, he was also very familiar with his business.

I saw him smile slightly, try to be as gentle as possible, not to scare this old man who didn't seem to be very bold, and said: "Don't be afraid, old man, you can call me Cheng Yun, if you have any questions, you can ask me first." Of course, you can continue to fix your car, I think it was too dark before, and it was not convenient for you to see things. ”

This is a preferential treatment for the elderly.

The old man looked at them blankly for a long time, then he exhaled a long breath, held one of the side boxes of the motorcycle with his backhand, and did not stand up, just sat on the ground, gasped for breath, and asked, "What is this place?"

"Anyway, this is no longer your world, you've come to a whole new world, and this is a transit point between the two worlds. ”

“？？”

The old man froze again, looked at them, and did not speak.

Cheng Yun didn't speak, giving him time to think.

After about a minute, the old man squirmed his lips and muttered, "It's not my world anymore......"

Cheng Yun nodded: "Yes." ”

I don't know if he accepted it, or if he was still in the stage where his brain didn't react.

It took about another minute or so before the old man opened his mouth again.

"Fake, right?"

"Really. ”

"That'...... What world is this?, am I dead?" There was not much fear in his tone, just a little regret.

"No, you're not dead, you're just coming to another world. It's the same world as yours, but it's a different world, a world where people from another world live. Cheng Yun tried his best to make his tone gentle, and he even squatted down to get himself close to the height of the old man sitting on the ground.

"So what is this...... What the world ......"

"Earth Universe, Earth. Cheng Yun said.

"I'm not dead, how did I come here?" The old man's voice still couldn't help but tremble a little, looking like an ordinary person, but Cheng Yan was still isolated by Cheng Yun with an invisible wall.

"Because of this ......" Cheng Yun raised his hand slightly, and a rusty ancient key fell on his hand from the sky, which he gently pinched with two fingers, showing it in front of the old man.

"You recognize it, right?" Cheng Yun asked.

"I don't recognize it, and I don't know what it is!" the old man's eyes widened.

"Well, that's weird, at least you got it from somewhere and came into contact with it, right?" Cheng Yun said.

"I picked it up, and I don't know what it is!" said the old man again.

"That's right, it's a ...... A space-time key, it brought you here. Cheng Yun tried his best to explain in words that were suitable for the old man's understanding, "I don't know whether to say that you are lucky or bad, in short, if you want to go back, you have to wait at least a little longer...... It's been more than a month. ”

"Go back?" muttered the old man, hesitating again, until he raised his head and asked again, "What you said is true?"

"Of course. ”

"Then will you take me out to see the world?" The old man glanced at the crystal ball floating beside him, he and Cheng Yun were talking, this crystal ball would sound synchronously, obviously this was some kind of translation device, he was a little curious, but not a lot, after all, he was old.

"Yes. ”

"I don't think I need to go back. The old man continued to mumble, "It doesn't make a difference anywhere......

"Why?" everyone Cheng Yun has ever met who doesn't want to go back has their own special reasons, "Don't you have any family over there?"

"Family...... Right in my car. ”

"In the car?" said Cheng Yan next to him, and at the same time looked at the motorcycle that looked quite heavy.

"Yes......"

The old man let out a long sigh, he was obviously very old, and even the tail note of his voice revealed a smell of sunset and twilight, as if there was an endless past behind him.

After speaking, he stood up with the side box, and without lifting the car, he opened the left side box, and inside was a box of photos and letters.

The specifications of this box are larger than the common side boxes in China, and there are many things naturally loaded.

The old man casually took out the largest photo frame and handed it to Cheng Yun, who was closest to him.

"My name is Jixu and this is my wife. ”

"We have no children in our lives, hehe, she can't have children. ”

Cheng Yun took the frame, on it was a photo of an old man in a sixtieth birthday, the photo was still quite new, the old man had short hair and smiled very kindly.

"She'......"

"Dead. The old man said very freely, "It's not good looking when it's old, I have a young one, I'll find it for you, cough cough cough ......"

Cheng Yun handed the photo to Cheng Yan, and then looked at him again.

It seems that after talking about his wife, he is a little more excited than just now.

Soon, another small photo frame was handed to Cheng Yun.

The photo on this is much older, not only in black and white, the picture quality is very poor, but also there are creases, and it can be seen that it was framed long after it was taken. And above is a little beauty in her twenties, not very tall, but her facial features are very good.

"It's beautiful!"

Cheng Yun praised it, and then handed the photo frame to Cheng Yan: "Then you don't have any other relatives or friends?"

"It's all here, cough cough ......"

The old man coughed as he covered his mouth as he pulled out a picture frame from the side box.

The photo above, also many years old, shows a group of young people, either riding motorcycles or sitting in the back seat, with a small lake in the background. Everyone was smiling happily and looking like they were young.

The old man smiled sadly: "Dead, all dead, I'm the only one left." ”

Cheng Yun pursed his lips, handed the photo frame to Cheng Yan again, and at the same time looked at the embarrassed old man and said, "With our text here, you can call it Ji Xu, the pronunciation is a little different, but it is also very similar." ”