The confusion in Su Yichen's eyes gradually faded. He looked up at the fern tree in front of him again, and then carefully looked at the rest of the trees in the forest. Among these trees, there are the more familiar magnolia, willow, maple, poplar, birch and even palms, etc., but compared with the outside world, these trees all look particularly tall and lush. Of course, in addition to these, there are also many plants similar to the fern tree in front of him. Although some of them are different, the obvious characteristics of the fern plants can still be seen from the shape of the leaves and roots.

His eyes gradually moved from the forest to the grassland, and then looked into the distance. Although Su Yichen didn't know how big this place was, at least he didn't see any margin in his vision. If this place was really made by man, then who has such incredible ability to build such a vast world under the ground? And where did the sky, the sun almost the same as the outside world, come from? What is the use of this place?

Countless answers formed a mystery, with thousands of threads but almost no clue. Neither Su Yichen nor Wan Changchun could explain these questions reasonably. At this time, the delusion that had flashed through Su Yichen's mind, which he had previously thought was unrealistic, suddenly emerged again.

"Are you talking about prehistoric humans or aliens?" After hearing Su Yichen's idea hesitation, Wan Changchun couldn't help frowning.

"Teacher Wan, I know that it is unscientific to say this, but from the current situation..." Wan Changchun is a scholar with a very rigorous academic research. Seeing him frowned deeply, Su Yichen thought he was a little unhappy with his "nonsense" and quickly tried to explain.

Who would have thought that Wan Changchun raised his hand and interrupted Su Yichen's words: "No! Although we need to use science as an argument for scientific research, it is not impossible to make bold assumptions in some cases. In fact, Xiao Su, your guess is also what I have thought about. From the outside world's discovery of that strange building to the present, everything we encountered is almost impossible to use current scientific theories to explain it. Then, we must break out of the original circles and look at the problem from another perspective, or even bolder guesses."

"Teacher Wan, then do you think that kind of guess is more likely to be possible?"

Wan Changchun thought about it and shook his head: "This is hard to say, I can only say that it is possible. Of course, maybe the final answer will be different from our guesses, but at least now, these two guesses can temporarily explain these problems."

Su Yichen nodded slightly and agreed with Wan Changchun's point of view. If we use this assumption to infer, then there are two possibilities for where they are now. The former is a ruin left by prehistoric humans, which can explain why plants that have already been extinct in the outside world are produced here. The other possibility is that a place similar to a biosphere built by aliens can also explain this problem. But the more critical problem is that no matter which one may be, there are defects.

The biggest flaw is why there are no animals in this place except plants, because no matter which possibility is judging from, even if prehistoric humans have become extinct or aliens leave here, at least animals will continue to reproduce in this place. Now, except for the plants that are eye-catching, there are no signs of animals. If it is due to some natural disasters and man-made disasters, then this place should be completely destroyed, and it will not be like this now.

This problem also troubles Wan Changchun. Unlike Su Yichen, before Su Yichen came, he studied the two giant trees. The size of these two giant trees really surprised him because he could not judge what kind of trees these two giant trees were. Moreover, their size was huge and their crowns were unimaginable. According to literature records, the largest tree on the earth was a giant pine in California, USA. This giant pine was as high as 100 meters, with a circumference of 34.1 meters, and its age was about 2,100 years.

Compared with this giant fir tree that has been recorded in human history, these two giant trees are only even better than that. After preliminary calculations, Wan Changchun had a circumference of the trunks of the two giant trees had exceeded 120 meters. As for the height, it is at least several times that of this number. The age of the tree cannot be tested for the time being, but it is not short. Moreover, Wan Changchun can conclude that these two giant trees will definitely not be fir trees, let alone banyan trees. Judging from its trunk characteristics and leaves, it seems to be a tree species that has never been seen. There is a strange red fruit on the tree, which is something he has never seen before.

For a moment, both Su Yichen and Wan Changchun fell silent. They each frowned and tried to figure out all this and find answers to explain these questions. Looking at them like this, Hu Zhijun, who was standing by, was a little anxious. He delayed a lot of time from the beginning of encountering the wolves along the way, and even lost Gudamai's life in the desert. He didn't want to go out as soon as possible, but instead considered what was not suitable for food and drink here. He really didn't understand why the experts' heads were different from their own.

Originally, Hu Zhijun didn't want to urge him, but time didn't wait for anyone. He was worried about the task and finally couldn't help asking.

"Leave? How to leave?" Wan Changchun was stunned when he heard Hu Zhijun's words.

Hu Zhijun said laughing and crying: "I said Lao Wan, you are still a big expert. Didn't Xiao Su say that he came from a fork in the road, and maybe the other passage is the way out."

"Yes!" Wan Changchun's eyes lit up, but what he thought of instantly was a little different from Hu Zhijun. Hu Zhijun planned to find a way out from another passage, and Wan Changchun also considered whether he could find an answer to explain all this in another passage.

At the same time, Su Yichen also thought of this and looked a little excited. The three of them quickly cleaned up and led the way back to the passage. Soon, they arrived at the passage hidden behind the rocks by the lake. When they opened the vines to see the passage, whether it was Wan Changchun or Hu Zhijun, they were amazed at the slight bright green light inside the passage.

Su Yichen led the way, Wan Changchun followed by Hu Zhijun, and the three of them entered the passage one after another. After walking forward and turning several turns, Su Yichen finally returned to the previous fork. At this time, the room was still exactly the same as when he left. Pointing to the room, Su Yichen told Wan Changchun that they had come down from there. If he guessed correctly, this room was probably an elevator-like lifting device that could pass it to the passage to the pyramid and the square.

Standing at the door of the room, Wan Changchun did not walk in, but looked at it carefully. In his opinion, although the pyramid and square depicted by Su Yichen were strange, it could not be as attractive as the other passage. Now, let’s explore the untraveled passage first, maybe it may surprise them.

When entering another passage, Hu Zhijun firmly demanded to take the lead because he believed that this passage had never been through and there was a danger. For the safety of the experts, it was most appropriate for him to explore the path. Su Yichen and Wan Changchun could only agree to Hu Zhijun's determination. In this way, Hu Zhijun entered the passage first, allowing Su Yichen to keep a distance from him, and the three of them gradually fumbled to the forcing.

There was almost no difference from the previous passage. There were also many bends ahead. The more you walked in, there was no danger along the way. Gradually, the three of them were holding their hearts slowly lowered. When they turned another corner, Hu Zhijun, who was walking in front, suddenly stopped for some reason, and then quickly took a big step back. Su Yichen, who was following behind, almost hit him.

"What's wrong with Lao Hu?"

"Be careful! There is someone in front!" Hu Zhijun pushed Su Yichen backwards, flashed sideways, and at the same time he took out the pistol that had been stuck around his waist.
Chapter completed!