Although I was very uncertain about my IQ, I still took the bronze medal from Grandpa Sun's hand, flattened, rectangular, no different from an ordinary keypendant, except for a few small holes on it, I couldn't see any clues at all.

I let out a long sigh of despair as I put the bronze medal aside.

"See what?" Grandpa Sun asked me.

I shook my head in fear, thinking to myself that you can't see the expression, "Except for those two lines of words and a few holes, I don't see any difference." I said in frustration.

"Show it to me." Xu Man took the bronze medal from my hand and looked at it carefully, I didn't know what she was looking at, anyway, I gave up.

"Perhaps, the problem really lies in these holes!" Xu Man said to me.

"Any questions?" Once again, I took the bronze medal.

"Look here, look here!" Xu Man pointed to the two holes above, and then to the other three, "There are five holes in total, and the distribution is very irregular. ”

"What's this, the previous smelting technology is not superb, and there are many vents on the metal, which are just vents."

"That's not right!" Xu Man shook his head and said, "If it was a vent, it wouldn't be polished so regularly!" If you look at the edges of these holes, they are all very smooth, and the vents are not so big! ”

"Well, too!" I looked again, and the holes were the size of a grain of rice, and they were all regular circles.

"And where the holes are on the bronze medal, I always feel as if they are going to tell us something!"

"So what does that tell us?" I'm puzzled.

Xu Man ignored me and continued to observe carefully, muttering to himself, "Kong, what is Kong for?" ”

I also thought about it along her train of thought, and also muttered, "What is the hole for, it is breathable, but who can use this thing to breathe?" ”

"It's not breathable, so it's breathable or something?" Xu Man glanced at me, and suddenly his eyes lit up, "Or is it something else?" ”

"And what else can you see?" I don't know what she means.

"In ancient times, there was an idiom called chiseling the wall to borrow light!" Xu Man was there to remind me.

"What do you mean? For light transmission? ”

"Zhang Yu, give me your phone." Xu Man said to Zhang Yu.

Zhang Yu was very obedient this time, and quickly took out his mobile phone, Xu Man turned on the mobile phone flashlight, pinched the corner of the bronze medal with his hand, and did not block those small holes, and then the bronze medal was placed parallel to the ground, and the light of the mobile phone was illuminated on the hole, and the light passed through the hole of the bronze medal, forming five lights on the ground.

These five bright positions are like five stars, and I can't see any clues, what does this mean? Could it be a formation?

My first reaction was whether this point of light could have anything to do with the four wreckage, but the four wreckage stayed there in a regular manner, and it wasn't the position on the light, and besides, the light was five, not four!

A bat "fluttered" on my head, as if it had pulled a piece of, "TMD." I couldn't help but curse, and the bat didn't care, just flapped its wings a few times and flew to the top of the cave.

Xu Man couldn't help laughing when he saw my embarrassed appearance, "This little guy is quite interesting!" She took the light of her phone's flashlight and shone it up, trying to shake the bat that wasn't very friendly to me.

But when she took this photo, she seemed to have made a new discovery, "What do you think is that?" ”

Just above the top of the cave, an outline is drawn in red thread, about the size of a bathtub, in the shape of a polygon.

The outline is so clear that it doesn't look like it was formed naturally, and I'm sure someone drew it, but who painted it? Why do they draw a polygon on it?

Xu Man pushed me, "A man, please get out of the way!" ”

"Oh? Good! "I'm a little blindsided.

After I got out of the way, Xu Man looked at the position I stepped on just now, and sure enough, there was a red mark.

Grandpa Sun remembered the treasure in his pocket, took out the shock disk from it, and put it in the position of the red sign.

I saw that the needle of the shock needle shook, but it didn't shake as much as the ghost hit the wall.

"Grandpa, what do you mean? We haven't moved, and it doesn't look like we've hit a wall by something! ”

There was not much space in this cave, except for Grandpa Sun who looked at the wreckage, the others barely moved.

"No, I'm making sure this place is the center of the hole." Grandpa Sun said.

No wonder Xu Man pushed me away just now, it turned out that she also felt that this was a center. "Oh? So what are you doing with this? Isn't this thing for ghosts hitting walls? I looked at the maze and said.

"The ghost hitting the wall is a maze, and the maze has no central magnetic field, so when the ghost hits the wall, you can see that the pointer has been shaking, and in a normal space, there will be an absolute center position, and this position is not necessarily the position that we feel with the naked eye."

Grandpa Sun knew that my eyes were confused, and knew that I definitely didn't understand, so he explained there, "It's like an irregularly shaped stone, the place where you think it is the center of gravity is not necessarily the center of gravity, the real center of gravity has to rely on gravity to find, and this is the role of the shock fan." ”

"You mean this thing is the way to determine the center of this cave! Hey, what a god! I exclaimed.

"At least in terms of composition, this place is!"

As we were saying this, the hands on the vibrator rotated clockwise and then counterclockwise, and then stood still.

The two rotations of the pointer are basically uniform and unhurried, "which means that the entire magnetic field around it is uniform, and it should be the center." "Grandpa Sun knows.

"Hmph, the ancients were really, this can be found, this cave shape is also irregular, like a polygon, how do you know that this is the center of gravity!"

After saying this, I suddenly realized something, just now I seem to have mentioned a word, yes, "polygon"!

I just walked in and looked around the edge of the cave, and the edge of the cave was exactly the shape of a polygon drawn in red lines on the top of the cave.

"Did you find anything?" Grandpa Sun asked me.

"Well, this is the map of the cave!" I pointed to the top of the cave and said to Grandpa Sun.

"Hey, it's really yours, you mean the plane structure of this cave just above the top of the cave, and the position we stand in is the center of the whole cave." Grandpa Sun praised me, and then asked, "So, what can you say?" ”

Everyone seems to be back to square one, yes! What does this mean?

"Alas! Can you hurry up, I can't go on like this! Zhang Yu shouted from the side.

More than half an hour has passed since we threw the copper coin, and the blue spots on Zhang Yu's body have spread from his neck to his shoulders.

Xu Man took the bronze medal and put it about a meter above the red sign on the ground, then turned on the mobile phone flashlight and shone it under the bronze medal, and a beam of light appeared in the five holes, and the beam shot directly above the cave.

Xu Man tried to adjust the upper and lower positions of the bronze medal, and something unexpected happened, but when the bronze medal was at the right height, these five lights corresponded to the five intersections on each side of the polygon, that is, the five top corners.

All four of us can be sure of what this must say.

"Isn't the five points on the map above corresponding to the five points in the cave?" Xu Man said to me.

"That's right, it must be so!" I almost jumped with excitement.

From the inside of the graph alone, these five are called to have four acute angles and one excellent angle, "Which one to see first?" I asked Grandpa Sun.

"Let's look at the biggest horn first!" Grandpa Sun pointed to the position corresponding to the horn.

We looked up and made sure of it, and walked over to the corresponding position of the horn, only to see a groove in the wall of the cave, and nothing special.

"I know that this mountain god won't tell us the answer easily, so let's start with an acute angle honestly!" Grandpa Sun sighed.

We followed the instructions of the figure on the top of the cave and walked to the nearest acute angle, and Grandpa Sun carefully knocked a hammer on the wall of the cave, and a stone fell in response.

There was a small skeleton inside, and everyone could see that it was the arm of one of the mutilated bones, and there was something firmly held in this arm.