The drizzle has been falling, neither getting heavier nor stopping.

Although the warmth of the protective clothing was very good, Chen Xin still felt a little cool.

"Whew... Whew..."Chen Xin's panting voice was a little rough, although the protective mask could effectively block the harmful components in the air, it also affected breathing somewhat.

It was fine before, but now as Chen Xin's breathing quickened after walking for a while, he felt a little out of breath.

Chen Xin wanted to find a place to sit down and rest and calm his breathing, but seeing the rain and sludge everywhere on the ground, he decided to keep walking.

After all, it's just a little breathing, Chen Xin used to travel to Shudi, he also had a similar experience, just go a little slower.

However, this also made Chen Xin wonder if he really lacked exercise as Qin Lan said, and when he traveled to Shudi, it was because of the altitude sickness caused by the high altitude and thin air in the local area.

Could it be that when a professional online writer neglects to exercise in the past few years, his physique has really deteriorated?

Chen Xin had such suspicions, and couldn't help but wonder if he should get a manpower generator to put in the shelter, and when he was fine, he stepped on the manpower generator, which could not only generate energy, but also exercise.

But just as Chen Xin was thinking like this, he suddenly stopped and raised his head to look at the sky.

The rain fell on the visor of the protective mask, leaving unsightly stains, but Chen Xin still looked at the sky intently, looking at the thick dust clouds on the gloomy and dark sky.

"Damn it! It's hypoxia! Chen Xin's brain was not stupid, he just subconsciously ignored this problem.

Who cares about the oxygen we breathe all the time? I'm afraid it's only when you really can't breathe that you realize you need oxygen, right?

When preparing for the construction of the shelter before the disaster, Chen Xin also subconsciously ignored this problem, and just prepared oxygen cylinders in the shelter.

But now when he realizes that he is suffering from a lack of oxygen, he reacts, when the plants on the surface have been burned by the fire and the sky has lost its sunlight, the air that we are most accustomed to has become the biggest problem to survive.

Human beings need oxygen to live, and any activity of the human body also needs oxygen to sustain it, and the more intense the activity, the more oxygen is consumed.

Without the photosynthesis of plants in nature, the oxygen in the atmosphere will gradually decrease as the surviving humans consume it.

Unless the clouds of dust in the sky clear, the sun shines on the earth again, allowing new plants to sprout and photosynthesize, the process will be irreversible.

If the surviving humans want to survive, they can only find a way to produce new oxygen.

Chen Xin himself is not worried about this problem, his shelter has a planting greenhouse, and under the light simulated by the fill light, all the crops will still photosynthesize, which is enough to maintain his oxygen consumption for the time being.

As for official shelters, Chen Xin feels that the state should take this issue into account, and the only thing that cannot be determined is whether the state will be able to solve this problem perfectly.

After all, the state has to think about all the survivors in the country, not a single shelter.

There are two common ways to prepare oxygen: physical oxygen production and chemical oxygen production, physical oxygen production is simply to collect the oxygen in the air to use it where oxygen is needed; Chemical oxygen production is to reduce the oxygen in carbon dioxide or other raw materials containing oxygen through chemical reactions to form new oxygen.

Both of these methods were widely used to produce oxygen before the disaster, but in the present apocalypse, they are not so applicable.

Physical oxygen production requires a lot of electricity and only extracts the original oxygen from the air, which is not suitable in the current environment where the oxygen content in the atmosphere is gradually decreasing.

As for chemical oxygen production, although it does not have the disadvantages of physical oxygen production, it also has disadvantages, that is, chemical oxygen production requires the consumption of chemical agents, and the cost is high, and it is not suitable for large-scale application at all.

Therefore, if the Yanguo government wants to solve this problem, it can only solve it by means other than these two means.

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"Finally the mission is complete!"

The SWAT team, which had completed the escort of the oxygen concentrators, returned to the shelter under the police station, and everyone relaxed.

Although most of the SWAT team members did not know what exactly the supplies they were escorting, they could guess that this was a very important material when they saw the armored train at the railway station and the formation of the escort this time.

So when escorting this batch of supplies, everyone was actually very nervous.

Now that the task has finally been completed, everyone is naturally relieved.

The group talked and laughed and walked to the area where the SWAT team was located, although this mission was not tiring, but under the high level of mental tension, everyone was a little hungry.

The food in the vault wasn't very good, but after the mission, it was a joy to have something to fill your stomach.

However, since the food eaten in the evacuation center is mainly emergency food that was stored before the disaster, there is a cafeteria, but in reality it is only used to distribute food rations, and there is no fire for cooking.

After all, fuel is precious now, and it's still a bit of a luxury to use it for cooking.

As for the greenhouses that have begun to produce mushrooms, as well as rats and bread worms in captivity, these foods have gradually begun to appear in the recipes of the shelters, but they have not yet reached the point where all SWAT team members can eat them.

"What do you have to eat today?" A SWAT team member hooked his friend's shoulder and asked him about it.

"I think it's fried lamb with green onions, and yesterday's shredded pork with Beijing sauce, so it's time to change the taste today."

His companions responded to his words, sounding like they were eating food, but in reality they were only talking about the taste of self-heating food.

In the two months since the disaster struck, everyone has not seen fresh food for a long time, except for mushrooms and rat meat.

Another SWAT team member on the side interjected: "I think there should be cabbage soup today, but yesterday we came back with a box of cabbage!" A whole box of fresh cabbage! ”

"Not really! Or I and the pillar carried it together, but it had to be two hundred pounds! "Next to him, a SWAT team member who also went to carry vegetables yesterday had his eyes lit up when he talked about those cabbages.

Not everyone knows the news of fresh vegetables, and now that they learned about it, many SWAT team members cheered excitedly: "Oh oh oh! I haven't smelled cabbage in two months! ”