In 2031, the Nuwa landed in Wenchang, Hainan Province, where six Chinese astronauts and space tourists set up a closed base, and using artificial insemination, 12 women gave birth to 120 fraternal twin offspring over the next decade. Of these, 59 were women. Using artificial insemination techniques and contraceptive measures, the remnants of the population try to choose sperm that are far away from each other for fertility. Fifty-nine young offspring were born from fraternal twins over a 20-year reproductive period between the ages of 20 and 40, and 1,800 offspring were born.

The reason why the first generation of female ancestors and the second generation of female ancestors voluntarily or forcibly acted as reproductive machines is that at least 50 members are required to maintain the normal reproduction of a population. If the first generation of female ancestors did not use the remaining reproductive period to scientifically arrange artificial conception, the following human offspring would inevitably become extinct due to genetic diseases and too few people.

In addition to other unrelated males, the sperm used for fertility in the first two generations also came from frozen sperm in the freezer of Wenchang Hospital. Although the city was paralyzed after the mass extinction, the freezer could not function. However, the subsequent large ice cap kept the freezer cold. Humans returning to the ground found partially surviving frozen sperm here, which made it possible for the Chinese to reproduce.

Since then, the population of the closed base has increased, and the artificial insemination has been abandoned and the pregnancy has been free. Human freedom and the rule of law were gradually restored, but marriage was dissolved. Before the mass extinction, there was an increase in the number of children born out of wedlock and out of wedlock, especially in Western and Northern Europe. After the mass extinction, the original marriage system disintegrated, and the single-parent family model became more popular.

In 2080 A.D., a large number of combustible ice deposits were discovered in the dark sands of Zengmu. In order to facilitate the mining of combustible ice, some humans have moved south to Sarawak, Malaysia, to establish a new closed base along the southern coast of the South China Sea. After 150 years, the closed base developed into a closed city of 400,000 people, which is now the new Fuzhou City.

In 2230 AD, the residents of Xinfuzhou were divided over whether to reuse nuclear power, and the two sides clashed over different views. In the end, a referendum was adopted to determine the ownership of the new Fuzhou City. Opposition to the return to nuclear power is in the majority, and the new city of Fuzhou has legislated a ban on nuclear power plants and the development of nuclear fusion. Supporters of the nuclear power plant left the city of New Fuzhou to establish the company of the future in Liaonei, 400 kilometers away, which is now the city of Liaonei.

The Riau nuclear power plant is located outside the dome and is buried 100 meters underground, surrounded by 20 meters of reinforced concrete.

Inside the nuclear power plant, located in the north, three guests were welcomed. Li Mu, Chiyo, and Lin Li visited this underground building under the guidance of the staff. When the three of them got together, they talked about what they had never seen a nuclear power plant like, so they decided to go on a trip together to see the legendary nuclear power plant.

"Nuclear fuel is shipped by sea from the uranium mines of Australia around the world and transshipped here through the city of Riau. The electricity generated today is still generated by uranium fission to generate heat, and the heated water becomes steam to propel steam turbines to generate electricity. The power generation efficiency is not as good as that of fuel cells, but it is better because nuclear fuel is sufficient, and after the combustible ice is used up, the nuclear fuel can continue to supply human needs for a thousand years. The staff introduced.

"Is this the source of the power that has destroyed the world? Now it's used to boil water. Chiyo couldn't help but sigh as she looked at the huge underground structure.

"The sword is not evil, it depends on how the person uses it. It would be a pity to supply humanity's energy needs for thousands of years, just because it would destroy the world. Li Mudao.

"Yes, nuclear power plants are good for closed cities. Today's fuel cell power plants also need to pump oxygen from the outside world, while nuclear power plants don't. Before the mass extinction, nuclear power could be used as an energy source for aircraft carriers and submarines, and the aircraft carrier itself was equivalent to a closed city. Lin Li's cute pink double ponytail swayed gently.

"In fact, the most suitable place to close the city is the nuclear fusion power station, but until now, there is still 50 years left for nuclear fusion to be used for civilian use." Li Mudao.

"Nuclear fusion technology is a key project of our company, and although everyone jokes that there are still 50 years left, we are indeed moving towards our goal step by step." Lin Li continued, "Of course, I don't know if I can see it in my lifetime. ”

"If there wasn't a mass extinction, now we should have done nuclear fusion." Thinking of the mass extinction 300 years ago, Li Mu regretted the interruption of human civilization.

A visit to the nuclear power plant is just the first stop on the trip. In later generations, many wealthy people liked to seek excitement, and it was the choice of many people to leave the glass cover of the city and explore in the wild.

The trio traveled upstream along the Chao Phraya River in a black motorhome. The motorhome is about the size of a bus and has two parts, the front is the cab and the rear is the bedroom. The car is prepared with food for three people for a month, with multiple generators and solar panels. Rescue tools and communication tools are available in multiple copies.

"Why does Chiyo prepare so much food?" Lin Li asked Chiyo, who was driving.

"Even if a mother and daughter have enough food for one person, whether they murder each other or give each other the opportunity, the result is that they cannot survive at the same time. And those who survive will undoubtedly have a very heavy psychological trauma, which cannot be repaired. Chiyo explained.

"There's only one best solution for this kind of thing, and that's to keep that from happening. So Chiyo prepares the food well to avoid a desperate situation, right? Li Mu said on the side.

"Yes." Chiyo nodded.

"I see." Lin Li suddenly realized.

"Tick." The on-board system prompt sounds.

"It's almost time to get to the scheduled camp, we can get off and rest later." Chiyo saw that on the navigation map, the RV was approaching the scheduled campsite. The campsite is a lakeside and is usually the first stop for adventurers on the Chao Phraya River route.

The lake is not too big, just about the same as Xuanwu Lake. There are not only mosses but also a lot of ferns on the lake's edge, which form a low shrub. The water of the lake is slightly blue, and the algae in the lake turn itself cyan in response to ultraviolet rays.

The RV was parked far away from the lake, and Li Mu was the first to get out of the car wearing a protective suit similar to a spacesuit, carrying a blue oxygen cylinder behind him. Li Mu was holding some triangular poles in his hands, and there was a camera on the poles.

"Komaki, put the camera 50 meters away from the car, and come back to get it." Chiyo sat in the cab and looked at the monitor and commanded.

"I'll make the food." Lin Li put on an apron and prepared dinner. The apron is worn on the petite Lin Li, which looks extremely cute.

"Xiaoli looks so cute in an apron." Chiyo saw Lin Li and shouted deliberately.

"I'll be right back." Li Mu's voice came from the display screen.

"You two." Lin Li waved the spoon in her hand, "If you make any more trouble, I won't get you anything to eat." ”

"Hahaha."

Outside the car, the sun was setting and the lake and sky were dyed red. Among the ferns, countless amphibious octopuses poked their heads out and stared at the glowing RV with big eyes.