I was very happy to see Xu Weiguo agree to Wu Lan.

"Brother, thank you!"

Wu Lan said seriously.

Xu Weiguo smiled and said, "Girl, why are you so serious all of a sudden? I'm even embarrassed."

"Since you call me brother, I will naturally try my best to help you."

Wu Lan nodded, "Brother, I found that you are closer than my own brother!"

"If my father saw you, he would probably think of you as his godson!"

Xu Weiguo quickly shook his head, "Xiaolan, we have agreed in advance! I am your brother and you are my sister, but if your father wants to take advantage of me, then I won't do it!"

Wu Lan smiled helplessly and said: "Brother, if my dad hears what you said, it will be very sad."

Xu Weiguo: "Why are you sad? What I said is the truth!"

"Okay, you've eaten this meal, and I promised you. Go home as soon as it's not too dark! Be careful on the road."

Wu Landu said: "Brother, you really want me to leave!"

"Then I won't leave. You said you have classes in the evening, so I have to stay and have classes!"

Xu Weiguo: "Are you serious?"

"Of course, now that my uncle is well and has gone back to his workplace, I don't have anything to do. It would be boring to go back so early. I might as well study with you here!" Wu Landao said: "Following you is better than following Wu Shixiong.

It’s much more interesting!”

"Okay!" Xu Weiguo nodded, "Since you want to stay and study, I can't drive you away. I'll send you back after class is over. But Ran Qiu's house is closer, so I have to send her off first.

You may have to follow us around for a while!"

Wu Lan nodded quickly, "Of course there is no problem!"

At this time, Du Yue came over and said, "Weiguo, Xiaolan, what are you talking about? You are so involved."

Xu Weiguo said helplessly: "This girl Xiaolan doesn't want to go back so early and has to study with us, so I have no choice but to agree to her."

"It's a good thing to study together!" Du Yue quickly reacted, "You are worried that Xiaolan will not be safe if she goes back alone, so we will send them together later."

Xu Weiguo nodded, "Yeah, that's what we decided at the beginning."

Wu Lan took Du Yue's arm and said, "Sister-in-law, you are so lucky to have found a good man like my brother. In the future, I will have to look for men better than people like this brother."

Du Yue smiled and nodded, "Your idea is very good, many people have said so, but there is only one Weiguo, and there are very few people who are as good as him. I advise you to lower your standards and be more careful.

Otherwise, I’m afraid I’ll become an old girl!”

Wu Lan: "...."

"Sister-in-law, I don't show off like you do!"

Just when Xu Weiguo and the other three were chatting happily.

Lou Xiao'e said: "Weiguo, what are you doing? Come here quickly, Ran Qiu has started class!"

"Come on, come on!" Du Yue quickly took Wu Lan's hand and left.

Xu Weiguo followed slowly behind.

Seeing Xu Weiguo coming over, Lou Xiao'e said: "Weiguo, Ran Qiu just told us about water. You can tell us more."

Xu Weiguo smiled and said, "Ran Qiu's explanation is relatively simple, but I may explain it more complicatedly!"

"It doesn't matter, I just like to listen to more complicated things." Lou Xiao'e said confidently.

"What are your opinions?" Xu Weiguo looked at the others.

"It's good to expand your knowledge more, I agree." Wu Lan nodded.

"I agree too." Du Yue.

"Brother Xu, just tell me, I want to hear it too!" Ran Qiu said.

"Okay, I'll talk about it!" Xu Weiguo nodded, "Water, pronounced shui, was first seen in oracle bone inscriptions in the Shang Dynasty. Its original meaning is river, and it is extended to refer to all waters; it is also extended to refer to colorless and odorless transparent liquid.

certain

Some liquid substances; and the level is derived from the fact that water is still and flat, and the meaning of measuring level with water is the so-called "accuracy" in "Shuowen Jiezi"; there is also swimming, one of the five elements, and the creatures living in various water bodies.

and other meanings."

"Ran Qiu has just talked about this, Wei Guo, you have to tell us something we don't know!" Lou Xiao'e said.

"Don't worry, let's do it little by little." Xu Weiguo smiled slightly, "Water is an inorganic substance composed of hydrogen and oxygen. It is non-toxic and drinkable. It is a colorless and odorless transparent liquid at normal temperature and pressure.

It is called the source of human life and an important substance for sustaining life, also called hydrogen oxide. Water is one of the most common substances on the earth, and about 71% of the earth’s surface is covered by water. It

It is an important resource for the survival of all life, including inorganic compounds, and is also the most important component of living organisms. Although its content in the air is small, it is an important component of the air. Pure water has very weak conductivity and is extremely

Weak electrolyte. The water in daily life has more anions and cations because it has dissolved other electrolytes, so it has more obvious conductivity."

"Water is a colorless, tasteless, and odorless liquid at room temperature. Water has the highest density at 3.98c. The density of solid water is smaller than that of liquid water, so ice can float on the water. When water freezes, its volume is slightly

There is an increase. Under standard atmospheric pressure, the boiling point of pure water is 100c and the freezing point is 0c. Moisture

The electrons are polar, that is, the positive and negative charge centers of water molecules do not overlap, which makes water a good solvent. Many common gases can be dissolved in water, such as ammonia, sulfur dioxide, carbon dioxide, nitrogen dioxide, etc. These

The solubility of gas is related to temperature, pressure, gas phase partial pressure and other factors."

"Water is a necessary substance for the normal metabolism of the human body. Under normal circumstances, the body must excrete about 1.5L of water through the skin, internal organs, lungs and kidneys every day to ensure that toxins are excreted from the body. Children's bodies contain 80% water, and the elderly's bodies contain 80% water.

There are 50% to 60% of water in the body, and the body of a normal middle-aged person contains 70% of water. Water has many important functions in the body.

Energy: Water is an important component of cell protoplasm; water acts as a solvent in the body, dissolving a variety of electrolytes; water acts as a transport in the body and can transfer nutrients, metabolic waste and endocrine substances; water has high thermal conductivity and specificity

Heat can be used as a "heat carrier" to transfer heat between the body and the skin surface, helping the human body regulate body temperature."

"There are many different understandings about the origin of water on the earth, each with its own reasons. But what the truth is, it remains for scientists to collect more objective evidence to uncover this mystery. As we all know, 72% of the earth's surface

The area is covered by water. However, where the water on the earth comes from has always been an unsolved mystery. Scientists have shown through isotope analysis of meteorites and earth's mantle rock samples that water is present on the earth.

It appeared much later than previously expected. This largely refutes the previous statement held by many scientists that "water was transformed from the ice on the surface of meteorites during the formation stage of the Earth." Water on Earth

The origin and formation time determine the direction of the evolution of the earth and the time when life originated. As for the source of water on the earth, the two most representative theories at present are the "exogenous theory" and the "endogenous theory".

As the name suggests, the exogenous theory believes that the water on the earth comes from outside the earth. One of the candidates for external water sources is comets and water-rich asteroids. The composition of comets known as "dirty snowballs" is

Water and interstellar dust, comets hitting the earth will bring a lot of water. Some water-rich asteroids fall to the earth and become meteorites, which also contain a certain amount of water.

Generally it is 0.5%~5%, and some can reach more than 10%, among which carbonaceous chondrites contain more water. Chondrites are the most common type of meteorite in the solar system, accounting for about 86% of the total number of all meteorites.

For this reason, some scientists believe that when extraterrestrial objects such as comets and asteroids hit the earth, they bring the frozen water resources into the earth's environment.

[A novel app that has been running stably for many years, comparable to the old version of the source-changing app, huanyuanapp.]

However, scientists have found that the chemical composition of most comet water does not match that of Earth's water. In addition, the above-mentioned scientists believe that since meteorites have fallen to the Earth during the Earth's formation stage, they should leave corresponding traces in the Earth's mantle.

chemical traces. If the water is indeed here

If it was brought to the earth by meteorites in the first stage, the isotope levels in the mantle and the isotope levels in the meteorites should be the same. However, when they compared and analyzed the ruthenium isotopes in the meteorites and the ruthenium isotopes in the earth's mantle, they found that the isotopes of the two were

There is no similarity in level.

According to this, scientists said that this proves that if water was indeed brought to the earth by comets or asteroids, the time when it came to the earth was not during the formation of the earth, but after the earth evolved to form the crust and mantle.

period. But it does not rule out another situation, that is, water was actually a component of interstellar dust at first, and the earth

The ball is composed of interstellar dust. Another candidate for the source of external water is the solar wind. The solar wind refers to the continuous flow of plasma particles radiated from the solar corona to the interplanetary space. It is a typical ionized atom and consists of about 90%

Composed of protons, 7% a particles and very small amounts of atomic nuclei of other elements.

Some scientists believe that the water on the earth is the masterpiece of the solar wind. The solar wind reaches the upper layer of the earth's atmosphere and brings a large number of hydrogen nuclei, carbon nuclei, oxygen nuclei and other atomic nuclei. These nuclei combine with electrons in the earth's atmosphere to form hydrogen atoms and carbon atoms.

atoms, oxygen atoms, etc. and then turn into water molecules through different chemical reactions. It is estimated that on the earth

In the upper atmosphere, almost 1.5 tons of this "cosmic water" are produced every year. This water falls to the earth in the form of rain and snow. More importantly, the ratio of hydrogen to tritium content in the earth's water is 6700:1.

The ratio of hydrogen to tritium on the surface of the sun is also very close, which fully demonstrates that the earth’s water comes from the solar wind.

However, the water formed by the solar wind is so small. In the 4.5 billion years of the earth's life history, it has only formed 6.75 billion tons of water, which is only a drop in the bucket of the current water storage on the earth's surface.

The theory of endogenous origin holds that the water on the earth comes from the earth itself. The earth was formed by the fractionation, collapse, and condensation of the original solar nebula gas and dust. After condensation, these planetesimals continued to gather to form the embryo of the planet, and then

It further expanded and grew to form the primitive earth. When the earth originated, the material that formed the earth contained water.

When the earth was formed, the temperature was very high. Water existed in the earth's crust and mantle under high pressure, or in the gaseous state in the earth's atmosphere. Later, as the temperature decreased, the water in the earth's atmosphere condensed and fell to the ground. Water in magma

It is also continuously released into the atmosphere with volcanic eruptions and geological activities, falling to the surface and gathering to the surface.

The water in low-lying areas forms rivers, lakes, and oceans. The amount of water contained in the earth's interior is huge. The magma deep underground contains abundant water. Some people speculate based on the amount of magma deep in the earth that within the 4.5 billion years of the earth's existence,

, the amount of water released by deep magma can reach half of the modern global ocean water.

There is also a theory that in the early stages of the formation of the earth, its interior contained very abundant hydrogen elements, which later reacted with oxygen in the mantle and eventually formed water.

Water and rock geoscientists tend to believe that the water on the earth comes from magma water during the evolution of the earth itself, while astronomers are more inclined to believe that water brought by comets and other impacts on the earth. No one is convinced by either view.

Many people seem to think that water in space is rare, but in fact water is very abundant in the solar system. For example, on our neighboring planet, Mars, many dry river beds, lakes, deltas, alluvial fans, etc. have been discovered on its surface, which shows that

There used to be a lot of water on the surface of Mars. Scientists also believe that there may be a lot of water underground and at the poles of Mars. In addition, some asteroids, Neptune
To be continued...