"You don't know, you're a little young, I guess you won't start working, but we should be assigned." Li Erniu explained.

Li Chengqian and the others all nodded, this doesn't matter, anyway, they are just waiting for the arrangement here.

Just when Li Chengqian and the others were thinking about these questions, at this moment, outside the wall of a special business firm with a plaque of "sewage treatment firm" outside the city of Yumen Pass, an old man with gray hair and a horse in his hand was looking at it.

The guy guarding the door of the business house hesitated for a moment, then walked over and asked, "This old man, do you have anything to do?" ”

"Oh, it's nothing, I just saw that a lot of cars transporting filth in the city are coming here, and I was a little curious for a while, and I wanted to ask." The old man asked with a smile.

"Oh, this matter, uncle, you're not my big man, are you?" The man immediately came to his senses, looked at the horses pulled behind the old man, and the things that resembled salutes carried behind the horses, and immediately asked.

"No, I came from the Tang Dynasty and traveled to the Western Regions." The old man said with a smile.

"Oh, that's it, in fact, this is the underground water system of our Yumen Pass, but the filth in the public toilet can't flow out of the city through the underground water system, but the leader has stipulated that all the filth is transported here by a special vehicle to clean up the filth." The guy said with a smile.

"Why is that?" The old man was a little curious.

"It's for public health, my husband is interested in this?" The guy asked curiously.

"Yes, in fact, my ancestors also studied medicine, so I am more interested in these aspects." The old man said with a smile.

"I see, do you want to come in and have a visit?" The guy immediately asked with a smile.

"Is that okay?" The old man was stunned for a moment and asked with some surprise.

"Of course, the leader said, everyone who is interested in this can come and visit, but most people will not come to see these filth, but all the officials of the Ministry of Health and those who want to open a medical center in Yumen Pass and other cities in Dahan need to come here to visit." The guy immediately explained.

"Oh? Why is that? The old man looked interested.

"That's the case, old man, why don't you come with me, and I'll let our supervisor here explain to you? There's a medical aspect involved, and I can't talk nonsense. The guy said a little embarrassedly, "I'm still in the process of learning, so I can't explain it to you." ”

"That's a good feeling, thank you Xiao Langjun for solving your doubts." The old man spoke.

"The old man is polite, dare to ask the old man's surname?" The man hurriedly saluted and asked.

"My surname is Sun, and my name is Sun Chang." The old man said with a smile.

"It turned out to be Mr. Sun, please." The guy made a gesture of please.

Sun Chang also led the horse into the gate, and when he entered the gate of the wall, Sun Chang found that this yard was much bigger than he imagined, and the more important thing was that the yard was not as dirty as he thought, or there was a peculiar smell, the whole yard was actually very clean, not to mention, and even the yard was planted with neat trees.

All the roads in the yard were covered with trees on both sides, and some of the ground was planted with alfalfa grass and the like, and there was a large building complex on the north side of the road more than 200 meters away from them.

"Is this really the place to dispose of filth?" Sun Chang asked with some surprise, because no matter how you look at it, this looks like a manor of a gate valve family, not like a place to dispose of filth.

"Of course, so that the old man knows, these are the orders of the chief, according to the words of the chief, the work is not divided into high and low, the whole Han can not run without people who do any work, and those who do any work are worthy of respect, although the work we do is dirty in the eyes of others, but we ourselves have to make it clean."

"The chief also said that you should learn to have fun in your work, such as the trees in the sewage treatment company, which were planted by the chief himself." The guy said with a smile.

"Leader Huo is a wise man." Sun Chang said seriously.

"Of course, there is no big man without a leader." The guy also laughed, "Uncle, our Director Zhou is here." ”

As they spoke, the two of them had almost walked in front of the complex, and a middle-aged man in his thirties walked out and was walking in this direction.

After the other party came over, the guy immediately bowed and said, "Director Zhou, this is the old man's name is Sun Chang, and he is a traveling Langzhong, and he wants to visit our firm." ”

"Uncle, this is Zhou Zhengzhou, the director of our sewage treatment firm."

"I've seen Director Zhou." Sun Chang waved his hand at the other party.

"Uncle Sun is polite, don't dare to be, you go, I'll take Uncle Sun to visit." Zhou Zheng said with a smile.

"Yes." The fellow immediately turned and left.

"My husband is from Datang?" Zhou Zheng asked with a smile after waiting for the guy to leave.

"Yes." Sun Chang nodded, "This time I originally wanted to travel to the Western Regions, and I passed by Yumen Pass and had some interest in the filth treatment of your Yumen Pass, so I came to take a look." ”

Zhou Zheng smiled and didn't say much, but he knew that this old man should also be a talent attracted by their Han's propaganda strategy, and the recruitment order promoted by the leader attracted a lot of talents from the Tang Dynasty.

The leader said that as long as it is a talent, whether it is Langzhong, now the Han is called a doctor, or a blacksmith, a carpenter, a mason, etc., as long as a skilled person comes to the Han, he will be given special hospitality, whether it is the distribution of land or the distribution of houses, there are preferential treatments.

And this kind of news with the Han caravan in Datang continues to deepen, this half a year has spread to many corners of the entire Datang, which has also attracted many Datang talents to Dahan, although Zhou Zheng is in charge of the sewage treatment firm, but he is actually accurate to be an official of the Ministry of Health established this year in Dahan.

This sewage treatment business is not only a sewage treatment business, like the group of buildings behind him, a considerable part of the medical research institute of the Ministry of Health, some of which collect many medical books, and some of which are laboratories, which are places for medical research, such as ...... Dissect the cadavers.

Therefore, Zhou Zheng did not expose this old man, but gave him a detailed visit to the sewage treatment firm.

"What does my husband want to know?" Zhou Zheng asked with a smile.

"Why do you plant so many trees here? Along the way, I saw that trees seemed to be planted near this Yumen Pass, or in all parts of the entire Han Dynasty, including both sides of the roads you built, as well as various residential areas and so on. Sun Chang asked a question that surprised Zhou Zheng.

Zhou Zheng paused for a moment before he spoke: "This is a long story. ”

"It's okay, the old man is also traveling all over the world anyway, as long as Director Zhou has time, the old man has plenty of time." Sun Chang laughed twice and said.

"Okay, then I'll tell my husband about this matter, I really have the honor to listen to the leader's lecture, so I know something. There are several reasons why I like to plant trees. Zhou Zheng smiled and spoke.

"The first point is that trees can solidify the soil and water, ensure that the soil is not lost, and improve the surrounding environment." Zhou Zheng said.

"What does this landline water, soil erosion mean?" Sun Chang was stunned for a moment and immediately asked.

"Can Mr. Sun notice that no matter how the river flows by the tree-planted river, it is difficult for the soil on both sides of the river bank to fall into the river, and the river will not be widened or diverted casually." Zhou Zheng said with a smile.

Sun Chang thought about it, he had seen too many things at his age, as soon as Zhou Zheng said this, Sun Chang pondered for a while and nodded: "It's true that these things are difficult to find every day, but this is indeed the case." ”

"Yes, according to the words of the chief, this is the role of fixing the water and soil and avoiding the passage of water and soil. Because the huge root system of the plant can stabilize the surrounding soil and prevent the soil from becoming loose, plus the plant needs water, and the plant can evaporate water during the daily growth process, and the more moisture in the air, the more humid the air is, and the air is humid, then rain will occur. ”

"It's a whole cycle, the more rain you get in a place, the more groundwater you have, the more groundwater you have, the easier it is for plants to survive, and then there's more moisture in the air, and it's a virtuous cycle." Zhou Zheng said with a smile.

They have all learned these things and theories, because the relationship between medicine and biology is inevitable, the sooner these things form a system, the better, Huo Gang may not understand this thing, but now with the development of glass, Dahan can actually study the telescope and magnifying glass, and the magnifying glass is studied, then it is not far from the microscope.

Modern super-powerful microscopes can't reach it, but it's not difficult to see cells with a microscope, especially plant cells because of their large size, which is easier to observe.

"Wait, that's what you're talking about...... Is it proven? Sun Chang was shocked.

"Of course. For example, the transpiration of plants has been proven. Zhou Zheng nodded.

"How was it verified?"

"That's the case, our big man has glass, does my husband know?" Zhou Zheng asked with a smile.

"Yes."

"That's good, we built two identical glass houses in the same place with glass, the glass houses were sealed, and after waiting for two days, we found that the inside of the glass houses was normal. Then we opened a glass house, put more than 20 pots of plants in it, and then sealed the glass house again. The next morning, we saw that there were already droplets of water on the glass house with plants that looked like dew. ”

"This proves that plants absorb water from the soil and evaporate it into the air during their daily growth, and we suspect that in this process, plants should produce some kind of nutrients that plants need." Zhou Zheng explained with a smile.