Yu Fei changed his mind and brought the problem of the same terrain into his hometown to think about it.

He is very familiar with the surroundings of Tai'e Village. He has been climbing and rolling in the mountains since he was a child, and he is familiar with almost every ravine and ridge there.

Then his thoughts opened up, because if he brought it to his hometown, he thought of the only way, which was to drill holes!

But of course there is no hole ready for Yu Fei to drill in this place, so if there is no hole, he looks for a hole. If the hole is not deep enough, he digs it himself!

Yu Fei thought of the caves that are very common in the mountains and are created by water flow. The entrance to such a cave is usually at a high place and the exit is in a general location. It is usually filled with rapid water flow after heavy rains. After being unable to find a vent, he developed it himself.

The way out.

When Yu Fei was a child, he often heard rumors from surrounding villages that children from this family accidentally fell into such a cave. When the adults from that family were working, they didn't notice that it had just rained and rushed out of the cave, and then people fell in.

Most of them are used by adults to teach their children to be careful about caves like this when they go crazy in the mountains.

Yu Fei once fell into a similar cave. It was the cave where he obtained the Dragon Ball. It was probably formed by the impact of water flow at first, and was finally artificially modified. I just don’t know when it was modified.

Yu Fei just wanted to catch this kind of cave and pass through the opponent's human wall of defense.

Looking at the extremely dense grass in front of me, this is actually a characteristic of this kind of cave entrance. Because of the sufficient water flow and the various mulch leaves brought, it will be covered with plants, making it difficult for people to discover.

Yu Fei gently pushed through the grass, and sure enough he saw a pitch-black sloping entrance on the ground. The entrance was four to five meters wide at its widest point and one or two meters at its narrowest point. It was definitely enough for a normal person to enter.

When Yu Fei saw such a cave entrance, he felt uncomfortable all over and hurriedly tightened the collar and cuffs of his clothes. Because such caves are usually very humid, there will be a lot of bugs inside.

After looking around, Yu Fei pushed aside the grass, took a step forward, and jumped down gently.

This was not a vertical cave, but more like an inclined slide. After Yu Fei put his feet into the soft soil, he simply sat on the ground and slid down.

But there is another problem, that is, this kind of cave is actually not very suitable for people to pass through, because water has no shape, so it can pass through as long as there is a gap when it flows, but people are different.

So while Yu Fei was sliding down, he took out the engineer shovel he had bought a long time ago from the Dragon Ball space and held it in his hand.

After sliding down for five or six meters, it stopped. It was pitch black below, but Yu Fei didn't need lighting equipment. He looked almost the same as during the day and could see everything clearly.

As expected, the cave in front is very narrow, like a cracked gap, with stones on both sides, thus forming such a terrain.

Yu Fei took out another insect repellent from the Dragon Ball space and sprayed a little on himself.

Because in this dark and humid place, there are more animals than people expected. All kinds of small scavenging insects and mosquitoes live here, and many of them have crawled onto Yu Fei's body without fear.

After spraying the insecticide, sure enough, many bugs escaped, and those that crawled on him also fell off.

Yu Fei carried the engineering shovel and walked along the crack that someone rushed out.

There is no such thing as a flat ground. There is mostly wet soil under your feet, which is a little higher when you walk on it, and there are even quagmires.

The further you go in, the more cold wind blows out. Because there is no longer sunlight, the low temperature here gradually drops.

This has no impact on Yu Fei at all. He just hopes that this cave will allow him to walk for a while, and it is best to exit.

Behind the human wall.

The impact effect of water flow is somewhat similar to that of humans. Picking up soft persimmons and squeezing them will not only flow to lower places, but also choose places with soft soil. Therefore, Yu Fei is destined to be unable to move forward in a straight line and has to turn around.

Yu Fei doesn't care about this. The biggest problem has arisen. The bigger problem is that it becomes narrower and narrower.

As the water flows, it continues to seep into the soil, and the amount of water is reduced, so the cave created by the impact shrinks.

At first, Yu Fei could walk straight forward, then he could only walk sideways, and finally he walked with his back hunched over, and there was a risk of getting pinched from time to time.

If he continues to shrink like this, Yu Fei will be unable to move forward. After all, he does not know Sun Wukong's seventy-two transformations and cannot shrink his body.

Yu Fei estimated that he finally stopped after walking a distance of thirty to forty meters in a straight line.

Now it is no longer a problem of narrowness, the water in front of me actually flows through the gaps in the rocks!

What a cheat!

Yu Fei watched as several stones were squeezed together in front of him, and the gaps formed were washed away by the water flow, and the water flow entered the gaps between the stones.

His engineer shoveled several times, trying to dig out one or two rocks to see what was going on behind him, and whether there were no more rocks and we could move forward.

But after thinking about it, he gave up again, because the soil here was soaked by the water and was very soft. If he dug hastily, it would very likely cause the cave created by the water to collapse. He would be digging his own grave.

However, Yu Fei's sight was blocked, but it did not affect his exploration of the terrain. He put his hands against the soil and used his spiritual energy as eyes to go behind the rocks.

Yu Fei prayed in his heart that this was not a place rich in stones. He hoped that these were just a few stones that happened to meet together, but that the whole thing behind them should not be covered with stone layers. Then his idea today would be dead and he would have to think of another way.

.

After more than ten seconds, Yu Fei's face lit up. Sure enough, God was not kidding him. Although there were a few stones behind the stone, there were not many. After that, there was a cave created by the impact.

Moreover, the cave behind is lower, and the water flowing out from the cracks in the stones creates a larger space, making it easier to walk.

However, it is very difficult to excavate these stones. If you change the geological environment here rashly, it may cause collapse here.

So Yu Fei carefully estimated how he could pass through this place based on his spiritual energy exploration.

After calculating for a long time, Yu Fei stared at the stone squeezed in the middle. After the stone was removed, the surrounding stones should be able to squeeze together and continue to form a relatively stable mechanical environment to prevent collapse.

.

However, this stone was sandwiched between several stones, so it was too difficult to remove it.

But Yu Fei simply didn't use any force to pull it out. Even if he pulled it out, it might cause other stones to move from their original positions and destroy the results he calculated.

So he walked over, put his hand on the stone, and tried to put it directly into the Dragon Ball Space. There were thirty things that could be acted upon by external forces. Yu Fei tried several times, but he felt that the Dragon Ball Space could not put the stone in. It seemed to be affected by it.

There is some kind of external force interference, which is not like actual force interference, but more like a rule.

It is unrealistic to directly enter the Dragon Ball space, so we have to find another way.

Yu Fei thought about it and decided to use his internal force to shatter the stone. However, this force was well controlled and must be used entirely on this stone without affecting other stones.

He closed his eyes and pondered for a while, constantly deducing in his mind what angle, how much force, how much dark energy and internal force should be used to shatter this fast stone.

To be honest with his brain, no

It's a computer and it can't perform modeling or simulation, so I can only make a rough estimate in my mind.

After thinking about it, Yu Fei put away his engineering shovel, took a deep breath of the slightly toxic air, and was ready to take action.

There are too many things that can be corroded here because of the impact of water flow, and the air circulation is not good. After the microorganisms decompose, some gases that are toxic to humans are produced.

This is just like the gas in a biogas pool. It is poisonous to ordinary people if it is inhaled. It can even explode if exposed to an open flame.

But there weren't many toxic gases here, and Yu Fei's body's purification ability was very strong, so he simply ignored the toxicity.

Everything was ready, and the rest was up to God. Yu Fei slowly retracted his right hand and concentrated his inner strength on his palm. The next moment, his eyes widened suddenly and he pushed his palm out.

Bo...

He slapped his palm on the stone, and a very weak sound came out, because most of the energy was sent to the middle of the stone by Yu Fei's dark energy.

If Yu Fei could control all his strength and not even make such a weak sound, this shows that there is still room for improvement in Yu Fei's control of strength.

The stone seemed to be motionless, but Yu Fei knew that the internal structure had begun to be destroyed. After waiting for a few seconds, a crisp clicking sound rang out in the silent cave.

Yu Fei became nervous. When this stone broke, it was the most likely time for the cave to collapse. If it really collapsed, this might be his tomb.

Although Yu Fei is very strong, under the mighty power of nature, he is actually just an ant. At this moment, Yu Fei is estimated to be at a depth of more than ten meters underground. Once the force of collapse is generated, even steel columns can bend and collapse.

After all, Yu Fei is still a mortal body, so how could he withstand it?

Click, click, click...

There were more and more cracks in the stone, and finally after seven or eight cracks appeared, it suddenly shattered!

After the surrounding stones lost their points of support, they immediately squeezed down towards the middle, and the big stone in the middle completely turned into fist-sized pieces.

It was too late, but it was too soon. Yu Fei was not unprepared. If this place collapsed, there was still a way to save himself, but he needed to be fast.

Yu Fei quickly pulled the rubble behind him and collected it into the Dragon Ball space. As long as he moved fast enough and cleaned up the rubble, he could get through. If this place collapsed, it probably wouldn't spread too far.

And sure enough, as Yu Fei predicted, dirt began to fall from the top of his head, and his speed became faster.

Finally, a space was cleared for Yu Fei to crawl in, and the next moment the soil above his head completely collapsed.

Behind the stone that Yu Fei smashed, there was another stone, but it didn't bear much force and could be slapped away with one palm.

At this moment, a small area of ​​collapse has begun above, which is also a characteristic of collapse. Generally, a small area collapses, further destroying the surrounding force balance, and then a more serious collapse.

Yu Fei didn't dare to think too much. He slapped the stone blocking the road with his palm and jumped directly over. The water flowing out of the stone in another part of the cave created a deep pool, and the height was lower than this one.

After Yu Fei landed, he found that this side had also begun to collapse. After all, the stability of the stone was in the middle of the two stages of collapse.

After Yu Fei landed, he quickly stood up and rushed forward. Logically speaking, the collapse would not be the collapse of the entire cave, but just this section. He would be safe if he escaped.

He ran very fast, like a swift cheetah, but he forgot one thing. After the cave collapsed, if there was no way forward, he would be blocked inside, and he would be in a state of chaos.
Chapter completed!