Is it oxygen that is blown out of the population As the population increases, will there not be enou

Inhalation: nitrogen (about 78%), oxygen (about 21%), water vapor (less than 1%), carbon dioxide (less than 1%).

Exhalation: nitrogen (about 78%), oxygen (about 21% slightly lower than when inhaled), water vapor (less than 1%), carbon dioxide (less than 1% slightly higher than when inhaled).

Rationale: Nitrogen accounts for about 78% of the air composition, oxygen accounts for about 21%, and all other gases together account for about 1%. Therefore, it is absolutely indisputable that nitrogen comes first and oxygen comes second in the inhaled air.

Typically, water vapor has a higher volume percentage than carbon dioxide.

Back to the first question. The air (gas mixture) inhaled by the human body is mainly used by oxygen, and nitrogen does not work. The gas passes through the tracheobronchioles and their branches and finally reaches the alveolar capillary network.

Oxygen is exchanged for carbon dioxide from the reflux of pulmonary artery blood (systemic venous blood), allowing the pulmonary veins to produce higher oxygen arterial blood for use throughout the body.

However, the amount of oxygen exchanged and the amount of carbon dioxide exchanged by a person every time he breathes is very small, and the change before and after does not exceed 1%, which does not affect the percentage ranking of the original gas at all.

Haha, if humans and animals exhale more carbon dioxide than oxygen, then there would be no oxygen on the earth for a long time.

Of the breath exhaled by a person, nitrogen is the most, followed by carbon dioxide, and oxygen is very little.

No, because the amount of oxygen on the earth is constant, oxygen will circulate in the environment, for example, oxygen will be consumed by human respiration and produced by plant photosynthesis, so the amount of oxygen in the air is relatively constant.

If there was no oxygen cycle, the earth would have been out of oxygen a long time ago, and would it have waited until now?

Wrong. Plants have a respiration effect, they can absorb carbon dioxide and release oxygen.

No, because the carbon dioxide we exhale is absorbed by the tree.

It is impossible for the population to grow indefinitely, beyond the carrying limit of the earth, either the universe will be immigrated, or human civilization will be destroyed.

As mentioned upstairs, marine algae are the main producers of oxygen in the atmosphere, and in fact, 20% of the oxygen content in the atmosphere is due to the contribution of seawater algae, and if they had not appeared, there would have only been anaerobic life on Earth.

But the contribution of terrestrial plants is not so small, after all, terrestrial plants are much more photosynthetically efficient, and algae can only produce oxygen in the euphotic layer of seawater, and the deep sunlight is too weak.

At present, the main source of oxygen on Earth is algae in the sea, and the contribution of plants on land is quite small.

Instead of worrying about running out of oxygen, worry about hunger and poverty caused by population growth.

The main organisms on Earth that consume oxygen are not humans, but microorganisms.

So, at this rate of population growth at the moment, there is no need to worry about running out of oxygen.

a. Air is necessary for the survival of human beings, animals and plants, and is also a very important natural resource, so the choice is correct

b. Since the photosynthesis of plants consumes carbon dioxide and produces oxygen, there is an oxygen cycle in the air, and the oxygen content in the air remains basically unchanged, so the option is wrong

c. Gases without color and odor are not necessarily air, but may also be gases such as hydrogen and carbon monoxide, so the choice is wrong

d. Under standard conditions, oxygen is a colorless and odorless gas, which can become liquid or solid under certain conditions, so the option is wrong

Therefore, a

Although the population density of ordinary trains is high and the air is dirty, it is not so hypoxic, and the train is not so tightly closed. Special trains, such as high-altitude trains, have an automatic oxygen supply system.

The carriages of ordinary trains are not sealed, and the wind comes in when the car is opened.

The high-speed rail carriage is sealed by air conditioning.

Experience, it feels very hot to take the train in winter, and it feels very cool to take the train in winter, so it is recommended to take the train.

One of the major functions of train air conditioning is the fresh air ventilation function.

Please rest assured of this. Although a large amount of oxygen is consumed on the earth, the green plants on the earth are also producing a large amount of oxygen through photosynthesis. In this way, the oxygen on Earth will never run out.