The walls and furnishings of the home are mainly beige tones, and the furniture style is fresh, the lines are simple, and the warmth and elegance are everywhere, which is the home of Li Huasheng, his wife and children. Sitting on the comfortable sofa at home, wearing lounge clothes, Li Xinjian, who looked gentle but childish, turned on the projector, and the three-dimensional model of the earth was projected in the air, and asked casually: "Sister, Dad came back from the moon base, has he passed through the earth's crust now?" "Let's revisit the structure of the Earth! I might be able to do it in tomorrow's final exam." Li Xinying, who is nine points similar to Li Xinjian's appearance, replied briskly. Looking at the three-dimensional projection of the Earth model, which was shown like this, she muttered softly.

Layer 1 is 500 to 1,000 km above the surface

(The atmosphere is now mainly made up of carbon dioxide and methane, while oxygen and water vapor have disappeared.) )

The second layer is about 0 to 60 km from the surface lithosphere

(Seventy percent of the lithosphere's surface area was once covered by seawater, but now it is dry.) )

The third layer is about 5 to 70 km from the surface of the earth's crust

(by rocks and magma formations)

The fourth layer is about 40 to 80 km above the surface of the mantle layer

(This layer is filled with red-hot liquid magma.) )

The fifth layer is about 80 to 100 km from the surface of the magnetosphere

(This layer is made up of melted liquid iron and nickel, and a large amount of electric current passes through the flowing iron and nickel, creating the Earth's magnetic field.) )

The sixth layer is a gravity layer about 100 to 140 km above the surface

(In this layer, gravity cancels out the centrifugal force in the Earth's interior, and people feel that gravity disappears and they enter a weightless state.) After crossing this layer, people are affected by the centrifugal force inside the earth, and stand on the ground on the inner side of the earth with their heads facing the center of the earth and their feet on the earth. )

The 7th layer is about 140 to 155 kilometers from the surface, and the first life protection layer

(Composed of reinforced ceramics and fiber-reinforced plastics, it is strong, thermally insulated, and insulated, protecting people's work and living areas.) )

The 8th floor is about 155 to 160 kilometers above the surface of the earth, where the work area is necessary for life

(This level is where people build the base needed to grow food and make a living.) )

The 9th layer is about 160 to 165 km from the surface of the earth

(A system of bullet trains for carrying people, and a system for transporting heavy materials for freight were established.) )

The 10th floor is about 165 to 170 kilometers from the surface of the earth

(Thousands of large cities have been established for human settlements, which are the main living and resting areas of the people.) )

The 11th layer is about 170 to 175 kilometers from the surface, and the second life protection layer is located

(Specially made solid reinforced gel-like soft rubber composition, insulation, heat insulation, shock absorption, waterproofing, to protect the ecological circle, to prevent soil erosion.) )

The 12th layer is about 175 to 2,200 km from the surface of the earth

(There are rivers, oceans, mountains, forests, fields, deserts and other lands, and all kinds of plants, insects and animals grow naturally, with only limited human intervention, and reproduce the earth's ecology in which living things are interdependent.) )

The diameter of the Earth's core is about 2,500 kilometers from the nuclear sun

(A precisely calculated gravitational force fixed to the ecosphere, infinitely massive, composed of dark matter called "Thousand Suns", about the same temperature as the surface of the Sun, about 5,700 degrees Kelvin.) The nuclear sun is surrounded by a shading curtain, which is controlled and adjusted by an intelligent computer system called "Silver Moon" to form the four seasons and the day-night climate cycle of the ecosystem. )

The diameter of the entrance and exit is about 6,000 square kilometers, the Arctic airport and the Antarctic airport

(The Land of the Centroid has two common north-south passages connecting the Earth's Centric and the Earth's surface, one is the "Arctic Airport" at the Arctic and the other is the "Antarctic Airport" at the Antarctic, and four emergency passages have been built on the equator, which will not be opened on weekdays and will only be activated when necessary.) )

"Sister, I've revisited the structure of the earth, and it seems that Dad will be home tomorrow afternoon!" Li Xinjian predicted. "Don't forget that Dad is going to be in the Arctic Airport Conditioning Room for 24 hours! I might not be home until the day after tomorrow!" Li Xinying added.

At this time, Li Xinying's optical brain bracelet rang the communication bell, and after it was connected, a three-dimensional projection of a friend appeared, and a girl with a ponytail and a little freckles on her face appeared in the projection. "Yingying, tomorrow is the final assessment, I'm nervous, why do I have to memorize and recite so many things, don't you have a light brain? I don't remember, don't you look up the light brain?" Li Xinying's friend Dai Nana complained loudly in a crying voice. Li Xinying calmly reassured, "Tomorrow will mainly assess the history of our Earth Ark and the current social system, which are all common sense questions, and they won't be too difficult, don't worry. I try to ask you, why do we call our inner world "Ark of the Earth?"

Dinana hesitated for a moment and said: "The "ark" in the name "Ark of the Earth" is derived from the "Ark of Noah" recorded in the Genesis of the Bible of Catholicism and Christianity, and we continue to use the "ark" to refer to our inner world, because the interior of the earth is now like a huge starry space carrier floating in space, like "Noah's Ark" has become a shelter for all living beings on the earth, not only the dwelling place of human beings, but we have recreated the ecological circle of the surface world in the inner world, so that all kinds of animals and plants can thrive, so it's called the "Ark of the Earth."

Li Xinying smiled slightly and teased: "I even remember the "Noah's Ark" in the history of religion, and the answer is good. Again, can you tell us about the origin and story of the upcoming Thanksgiving?"

Dinana smiled happily, "Will the content of the assessment be so simple? I almost forgot that November 11 of this month is our annual "Thanksgiving Day", and this year's "Thanksgiving" celebration is especially grand, because this year is the 10,000th year of the geocentric calendar, which means that we all mankind has entered the 10,000th year of migration to the inner world. I guess the origin of "Thanksgiving" is really a popular exam topic? Yingying, why don't you try to answer and give me a reference?"

Li Xinying thought for a while and said softly, ""Thanksgiving Day was originally a national holiday in one of the countries of the surface world, the United States, to thank God for the blessing of a good harvest of the year. Thanksgiving Day in the United States is celebrated on the fourth Thursday of November each year. In 1620 A.D., the Mayflower arrived in the Americas laden with Puritans. In the winter of that year, many people were suffering from hunger and cold, and died of disease. With the help of the Indians, the newcomers learned to hunt, grow corn and pumpkins, and usher in a bumper harvest the following year. On harvest celebrations, the new Europeans invited Indians to come and thank God for their blessings, which became the origin of "Thanksgiving."

Li Xinying took a second look at her thoughts and continued: "And the "Thanksgiving Day" in our inner world originated 10,000 years ago, when the surface world was on the verge of extinction due to human economic activities and greenhouse gas emissions, which led to the greenhouse effect, the glaciers in the north and south poles of the surface world melted, and the ocean inundated islands and coastal cities, extreme climate change, coupled with human pollution of the ocean, microplastic particles and garbage filled the coast, a large number of animals and plants died, and human beings were also on the verge of extinction, and the number of human beings was sharply reduced, leaving only 1 billion people in the world. At this time, God sent Eve's reincarnated human mother, "Liujin", and Adam's reincarnated human father, "Harumi", to this devastated land and gave them the divine key to open the door to the inner world. Led by the descendants of Atlantis, who have moved to the depths of the ocean and guarded the entrance to the Inner Earth for generations, Flowing Gold and Harumi opened the gates of the North Pole of the Inner Earth, and the humans who survived on the surface of the Earth 10,000 years ago gradually moved to the Inner Earth, where the Inner Earth was managed by an intelligent brain called the Silver Moon and energy came from the nuclear sun called the Thousand Suns. On November 11, the first year of the earth's centric calendar, most of the human beings on the surface reached the 10th floor of the inner world's living quarters, settled down initially, and established dozens of small living bases, and designated November 11 as "Thanksgiving" to thank God for giving the "Earth Ark" the promised land. At that time, the inner world of the earth was in ruins, there was no thriving ecosystem, no cities for human habitation, and food, water and air were scarce. With the help of the artificial intelligence "Silver Moon", the mother of mankind "Liujin", and the father of mankind "Harumi", it has taken 2,000 years to introduce all the air and water resources on the surface to the inner world of the earth, and it has taken another 1,000 years to establish a food planting base in the work area necessary for life, and gradually build a human city with transportation systems and residential areas. It took another 4,000 years to design and establish the geocentric biosphere, so that the various species of plants and animals and DNA stored in the geocentric species laboratory can be reborn and interdependent in the geocentric biosphere. On November 11, the 9th millennium of the geocentric calendar, "Thanksgiving", the mother of mankind "Liujin" and the father of mankind "Harumi" saw that the "Ark of the Earth" was completed and celebrated "Thanksgiving" with mankind, and fell into a deep sleep. Therefore, "Thanksgiving" should not only pray to God for gratitude, but also thank the mother of mankind, "Liujin", and the father of mankind, "Harumi", who will never abandon mankind, and reunite the family on that day, and before the dinner, light 3 candles to offer flowers, and pray in the candlelight for thanksgiving."

Dinana clapped her hands and smiled, "You are worthy of being a top student, and the explanation is detailed, no wonder you are so confident in tomorrow's assessment."

Li Zhijian, the younger brother who listened patiently, smiled, took a sip of water, and heard the sound of the electronic sensor opening at the door of the house, so he said loudly, "Is Dad coming home?" But take a second look, it turns out that it was my mother who came back! Li Ying said to Dai Nana, "Mom is back, Nana will see you tomorrow when she goes to school for the assessment, go to bed early tonight, and relax your mood!" I'll see you tomorrow."