The team was quiet. In addition to the chaotic and light footsteps, Gu Fengchun also heard the slightly heavy breathing of everyone. The team had advanced for about three or four miles, and along the way, Gu Fengchun did not give up observing the surrounding environment.

After spiraling up from the underwater staircase, Gu Fengchun found that this karst cave was actually artificially developed, but due to geological evolution, it gradually evolved into a large karst cave. As we move forward, the space around this area has changed from large to smaller. However, Gu Fengchun believes very much that the distance he has traveled now is actually very small, and he is far from reaching the end. Gu Fengchun was not guessing for no reason, but he understood that this cave was actually under the bronze temple, and the temple was already made of bronze, so such a secret place below would naturally not be very rough. The reason why it's so rough here is probably because it's not the point, it's still far away.

"Feng Chun, it seems that something is wrong!" Xiao Zhonghua deliberately walked side by side with him in order to protect his safety.

"How?" Gu Fengchun has great respect for Xiao Zhonghua. I also take what he says very seriously.

"I feel a little bit of trouble breathing, I don't know if everyone is like me." Xiao Zhonghua said. At this time, everyone's masks had been taken off, and the air quality in the cave was good, so in order to save not much oxygen left.

When Gu Fengchun heard this, he immediately became vigilant. To say that there is poisonous gas in this cave is a very reasonable thing. If nothing else, the stone stalactite alone is calcium carbonate, which contains a lot of carbon dioxide, and if there is no large amount of carbon dioxide in it, it is unlikely that the stone stalactites will be formed.

Gu Fengchun looked around, and everyone said that there were signs of depression. Only he didn't feel anything wrong.

"Everyone put on their masks and filtered the air while the oxygen supply inside was used as a consumption for breathing." Gu Fengchun didn't dare to be sloppy in this matter.

"There's not enough oxygen." Tang Maiqiu said with a sad face. He is not much different from Xiao Zhonghua and others, Xiao Zhonghua and others have taken immortal medicine, and their bodies are inherently antioxidants, and they naturally don't need much oxygen, but Tang Maiqiu is a very normal person, and the amount of exercise along the way is very intense, so the oxygen consumed is much more than that of ordinary people. Not just one Don Mai Cho, but so did Nelson. Strangely, the merman and Soren Gyatso didn't feel this way. However, Gu Fengchun also knows that the merman is originally an aquarium and can breathe naturally in the water, while Soren Gyatso has lived in a hypoxic place on the plateau for generations, with low oxygen content, and for him, he still has the ability to adapt.

Tang Maiqiu's words made Gu Fengchun very difficult. When Tang Maiqiu said this, he knew that this was not an individual phenomenon, but a crisis facing the whole world. Gu Fengchun glanced at Luo Xiaodan, and saw that Luo Xiaodan's face was slightly pale. However, Luo Xiaodan seems to have a corresponding solution, she looked at Gu Fengchun and said: "I was also a little depressed just now, but I took a little Xuezhi in my mouth, and the feeling of being depressed disappeared." ”

Gu Fengchun was stunned for a moment, he would never have thought of replacing air with food. This should just be Luo Xiaodan's way to coax him. This can only show that Luo Xiaodan's situation is even less optimistic.

"Everyone, hurry up!" Gu Fengchun's face sank and said. "This section of the area is the most lengthy and calm, so the silt is easy to collect, as long as we pass here, there should be a vent!" Gu Fengchun had to draw a big cake for everyone. At this time, there is no possibility of going back, and there is only one way to go to the dark. He only hoped that Chen Si would wake up early and give him an idea. Only then did Gu Fengchun feel how difficult it was to be the decision-maker of the team.

After listening to his words, everyone was convinced. You know, he drew up the map of the entire temple. So his words are not questioned by everyone. Even if they questioned it, they didn't dare to say it to their faces, because everyone knew that there was no room for any retreat except to move forward.

"Old Tang, how long can your oxygen supply last?" Gu Fengchun asked with a solemn face.

"About half an hour. However, with the air filtered by the filter membrane, it can last at least two hours. ”

"What about you? Little Dan. Gu Fengchun's eyes looked at Luo Xiaodan. Luo Xiaodan said: "There were no questions for three hours. ”

Hearing the words of the two, Gu Fengchun felt a little relieved and said, "At our current speed, an hour is enough to find a new passage and air outlet." ”

"God, I'll be able to hold on for an hour at most." Nelson said bitterly when he saw that Gu Fengchun had forgotten him. He was a large physique, needed a lot of food, and had an equally great need for oxygen.

"Take a bite of Xuezhi and bite into your mouth." Gu Fengchun suddenly remembered Luo Xiaodan's words and said to Nelson.

Nelson rolled his eyes, he came from the most technologically advanced country in the United States, and he received a systematic scientific education since he was a child, and he had never heard that eating food could replace the body's need for oxygen. However, after Gu Fengchun finished jokingly, he was stunned.

"Xiao Dan, are you telling the truth?" Gu Fengchun said with a solemn face, as if he had discovered something.

"yes, you think I can't lie to you?" Luo Xiaodan frowned.

Gu Fengchun didn't answer, took out a piece of Xuezhi from his arms, and put it in his mouth. His mask had already been put on Chen Si's head. But along the way, everyone also noticed his strangeness, and he was supported by a tattered mask without oxygen supply in the water for half an hour, so it is not surprising that he is still safe and sound.

Chewing Xuezhi slowly, Gu Fengchun also felt that his breathing and heartbeat slowed down a lot. He is sensitive to his own body, and he is aware of the changes that occur in his body.

"I see." Gu Fengchun said with a happy face; "This Xuezhi has an antioxidant function, which should replace some of the oxygen functions in the human body." Thinking of this, he couldn't help but think of another question, this Xuezhi is so miraculous, could it be one of the prescriptions in the elixir of immortality? Because the greatest function of the immortal elixir is to prolong the oxidation time and regeneration function of the cells, but this conjecture can only be known after Chen Si, who is familiar with this prescription, wakes up.

But he was right. This Xuezhi is indeed one of the countless miraculous medicines in the immortal elixir. Chen Si searched for many years in the Snow Mountains of Huijiang before he found a little, which is as much as in this cave. If Chen Si saw everyone coming to eat this, he would have to scold everyone for eating peonies.

There will be a change later.