After writing down some questions raised by Ziyang taixuan, Yang Tian considered and asked this world common sense question.

This makes Hui echan look at Yang Tian, just like watching aliens.

Because Yang Tian took the task, although the people of the rune department thought it was impossible to complete it, the rune department still arranged accommodation for Yang Tian.

It was a simple room, but it was cleaned up by Kata.

Kata is determined to mix with Yang Tian, because he thinks Yang Tian has a bright future. After Yang Tian rises, he can enjoy all the benefits from his fingers.

Took a night off.

The next day, Yang Tian didn\'t go to the room where Ziyang taixuan worked. Instead, under the guidance of Kacha, he went to the clan bank and replaced ten life crystals with lice crystals.

When Yang Tian was in the mine, the lice crystals he collected were the size of rice grains and in the shape of lavender granules. The lice crystals replaced by the bank were processed in a special way and have two shapes.

One is a long strip, about five centimeters long, with thick and thin fingers. The other is a round bead twice as big as a rice grain.

One source grade life crystal can be exchanged for 50 long strip-shaped lice crystals or 250 round bead shaped lice crystals.

In other words, fifty bead shaped lice crystals are equal to a long strip-shaped lice crystal.

Long strip-shaped lice crystals are generally used for large transactions, while round bead shaped lice crystals can be used to buy articles of low value.

Yang Tian replaced 500 round bead shaped lice crystals and 400 long strip-shaped lice crystals.

In addition to exchanging lice crystals, there is a special paper money that can circulate throughout the inflammatory region. Most of the ordinary people in the ethnic areas use paper money.

Practitioners have money and storage tools, so it is more convenient to use them.

But for ordinary humans, without storage tools, lice crystals are easy to fall and inconvenient to carry.

The wages of Kacha and others are also paid in paper money. Of course, you can also replace the paper with a piece of paper of equal value.

Kata has a storage ring with small storage space. Every time he gets paid, he changes it to lice crystal at the first time.

After staying in Huie\'s house for more than ten years, the lice crystal accumulated by Kata is not one tenth of the lice crystal that Yang Tian has changed to now.

A total of 18 life crystals, Yang Tian changed ten, and the remaining eight were left for Xiaoqinglong.

Although the little green dragon swallowed eight life crystals in the Guiyuan realm, and the energy obtained was not enough to promote it to the realm, it was better than not, wasn\'t it?

For example, if you are tired after fighting, you can use it to replenish energy for the little green dragon.

When Yang Tian told Xiaoqinglong to leave eight life crystals as snacks, Kata\'s eyes were red with envy. Xiaoqinglong responded to Kata\'s proud eyes.

Every time he looks at katcha, little Qinglong thinks of the fat man in Ju Liang City.

"In fact, before the animal tide, the ethnic land was very prosperous. There were shops everywhere, pedestrians in the streets, people next to people..."

While walking, he saw the broken scenes around him. Kata described the scene before the animal tide for Yang Tian.

"With such a big family and so many people, what do we eat?" said Kata, and Yang Tian asked curiously.

Katcha Road: "Planting! After a small lice crystal is dissolved in water in a special way, it can make a \'strong valley\' produce enough grain for a family of three in a month. As for other foods, some are planted in the same way as growing strong Valley, and some are wild fruits picked by practitioners in the forest far away and animal meat obtained by hunting exotic animals."

When Kata said this, Yang Tian finally remembered that when eating, there would be a big, smaller than football food on the plate, which tasted like sweet potato.

Originally, this is Zhuang Gu.

Zhuang Gu has a purple shell. After peeling off, it is crystal white, like pearls.

It tastes sweet when you eat it in your mouth.

An ordinary human can maintain the energy needed for production and life in a day by eating about two a day.

"Take me to have a look!" curious, Yang Tian said eagerly to Kata.

Kata nodded and took Yang TianChao to the center of the clan.

After passing the position of the fourth parapet, there are strong Valley trees thicker than adults\' thighs.

The leaves of this tree are very large and thick, light green and palm size. The trees are densely covered with strong valleys. There are at least hundreds of strong valleys on a tree.

The technical strip of the tree is very hard. A technical strip thinner than a finger can hang more than ten strong valleys on it, which looks very strong. Maybe this is the origin of the name of this kind of tree!

The strong Valley produced by this tree can allow an adult to survive for at least half a year.

Look at the roots of the trees. The surrounding of each tree is surrounded by bluestones. There is black soil inside. It is obvious that it has just been relaxed.

"What are the growth conditions of this tree?" Yang Tian asked curiously.

"It doesn\'t require much. It only needs a moment of sunshine every day. However, it is afraid of cold," katcha said

"Can it be planted underground?" Yang Tian said again.

"If it can be exposed to the sun," katcha said

The word "sunshine" here means the same as on earth. It is the light cast by stars in the sky.

After seeing this kind of trees, Yang Tian felt that people in this world are so happy that they don\'t have to worry about food at all.

No wonder people don\'t get sick. These foods are really green food, which absorb the energy of lice crystal. Ordinary humans eat such food, which is equivalent to indirectly absorbing the energy of lice crystal.

Although the amount is small, it can also keep people strong.

In the next few days, Yang Tian wandered around the family land.

Because the designed underground city should also consider people\'s production and life.

Just like Zhuang Gu, the built underground city must use runes to project the light of stars into the city in order to meet the conditions for the growth of Zhuang Gu.

……

The ten days agreed with Huie Miaomiao soon passed seven days.

On the eighth day, after Yang Tian went out for a walk, he went to the "studio" of Ziyang taixuan again.

When Yang Tian went out these days, although only Kata followed him, someone always looked at Yang Tian.

At this time, the singular program has calculated the design drawing.

Yang Tian enters the room of Ziyang taixuan. There is no one inside. Yang Tian searched for a long time and finally found several large, blank papers.

The family land model placed in the middle of the house has been removed, and Yang Tianzheng is good for drawing.

Of course, the process of drawing is a strange program to control Yang Tian\'s body and describe it on the drawing.

Yang Tian and Kata had just paved the drawing when the door was pushed open.

First came Ziyang taixuan, then a strange old man in red robe, followed by Hui echan, and then a large group of runes.

Ziyang taixuan didn\'t say anything. The strange old man came to Yang Tian and said faintly to Yang Tian: "don\'t be busy drawing the design drawing first. I\'ll beat you first. Besides, I\'ll fight with you! If you lose, leave the rune division immediately. If you win, I\'ll listen to you."

"Good! Good!"

When there was excitement to see, Hui echan clapped his hands.

Yang Tian scratched his head and opened his eyes to look at the strange old man... What\'s the situation!