We breathe the fresh air below the mountain.

воздух means air.

Air (k not k not kōng qì), the "life gas" we breathe every day, covers the earth's surface layer by layer, is transparent, colorless and tasteless, and is mainly composed of nitrogen and oxygen, which has an important impact on human survival and production.

Air refers to the mixture of gases in the earth's atmosphere, so air belongs to the mixture, which is mainly composed of nitrogen, oxygen, rare gases (helium, neon, argon, krypton, xenon, radon), carbon dioxide and other substances (such as water vapor and impurities). Among them, the volume fraction of nitrogen is about 78%, the volume fraction of oxygen is about 2 1%, the volume fraction of rare gases (helium, neon, argon, krypton, xenon and radon) is about 0.934%, the volume fraction of carbon dioxide is about 0.04% (the latest data of 2065438+07), and other substances (such as water vapor) The composition of air is not fixed. With the change of altitude and air pressure, the composition ratio of air will also change. But for a long time, people always thought that air was a single substance, until French scientist lavoisier first came to the conclusion that air was composed of oxygen and nitrogen through experiments. At the end of 19, scientists found that rare gases such as helium, argon and xenon existed in the air through a large number of experiments.

In the natural state, air is colorless and tasteless.

Oxygen in the air is necessary for all aerobic organisms. All animals need to breathe oxygen, so do green plants. In addition, green plants use carbon dioxide in the air for photosynthesis, and air is almost the only source of carbon dioxide needed by all plants.

This layer of air is the bottom of the atmosphere from the ground to 10~ 12 km, which is called the troposphere. Major weather phenomena such as clouds, rain, snow and hail all occur in this layer. The layer about 50 kilometers above the troposphere is called the stratosphere. The air in the stratosphere is much thinner than that in the troposphere, and there is little water vapor and dust in the troposphere, so there are few weather phenomena. From above the stratosphere to 80 kilometers, some people call it the mesosphere, and the temperature of this layer decreases with height. The space between 80 km and 500 km is called the thermosphere, and the temperature in this layer is very high, which varies greatly from day to night.

This layer from about 50 km above the ground to about 1000 km high is called the ionosphere. Beautiful auroras appear in the ionosphere.

More than 500 kilometers above the ground, it is called the outer atmosphere, also called the magnetosphere. It is the outermost layer of the atmosphere and the transition zone from the atmosphere to interstellar space. There is no clear boundary outside. In general, the upper limit is low near the geomagnetic pole, and it is about 9~ 10 radius of the earth high above the near-magnetic equator, in other words, it is about 65,000 kilometers high. The air here is extremely thin.

Air is a colorless and odorless gas.

At 0℃ and standard atmospheric pressure (1.013x10.5pa), the air density is1.29kg/m3. The state of gas at 0℃ and a standard atmospheric pressure is called standard configuration, and air can be regarded as an ideal gas at standard configuration, with a molar volume of 22.4L/ mol.

The specific heat capacity of air is related to temperature. When the temperature is 250K, the specific heat capacity of air at constant pressure cp= 1.003kJ/(kg*K). At 300K, the specific heat capacity of air at constant pressure cp= 1.005kJ/(kg*K).

The impedance of air is about 377 ohms.

The relative molecular mass of air is 29.

Air at room temperature is colorless and odorless gas, while liquid air is light blue liquid, which is easy to flow. Generally, when air is liquefied, carbon dioxide has been removed, so the components of liquid air are 20.95% oxygen, 78. 12% nitrogen and 0.93% argon, and other components are few, which can be omitted.

In the standard state, the speed of sound of air is 331.5m/s.

The molar mass of dry air was 28.9634 g/mol.

In the standard state, the refractive index of air to visible light is about 1.00029. It varies with air pressure, temperature and air composition. In particular, humidity has a great influence on the refractive index, and the corresponding speed of light will also change in the air.

/v/ is the phoneme of the Russian fricative sound of lips and teeth. When pronouncing, the upper teeth contact the inner side of the lower lip, air flows through the gap between the lips and teeth to form sound, and the vocal cords vibrate. For example:

в вь

ва во ву вэ вы вя вё вю ве ви вья вьё вью вье вьи

фа ва фо во фу ву фэ вэ фы вы фё вё фю вю фе ве фи ви

дв 10722

Moscow

вам You (third grid)

васс You (fourth grid)

вот This is it.

Sorry, guys.

выставка exhibition.

I am the man, Vera.

вечером at night.

I'm четверг, Thursday.

I have a spring.

In the spring.

I'm виктор Victor.

I'm sorry, Vega

ивём (first person plural present tense)

ивёт (third person singular present tense)

I hope it can help you solve the problem.