What exactly is PM2 5 Read answer 30

Refers to particulate matter in the atmosphere that is less than or equal to a micron in diameter, also known as particulate matter that can enter the lungs. Its diameter is less than 1 20 of the thickness of a human hair. Compared with coarser atmospheric particulate matter, the particle size is small, rich in a large number of toxic and harmful substances, and the residence time in the atmosphere is long and the transportation distance is long.

Pick D.

The mistake is that "due to the small size of the particles, the effect on air visibility is relatively weak." "Concentrations that rise to a certain level can lead to reduced visibility and even affect everyday life. EG: Smog in Beijing. All other options are correct.

Fine particulate matter is also known as fine particles, fine particles, . Fine particulate matter refers to particulate matter in ambient air with an aerodynamic equivalent diameter of less than or equal to microns. It can be suspended in the air for a long time, and the higher its concentration in the air, the more serious the air pollution.

Although it is only a small component of the Earth's atmosphere, it has important implications for air quality and visibility.

Compared with coarser atmospheric particulate matter, it has a smaller particle size, a large area, strong activity, and is easy to attach toxic and harmful substances (such as heavy metals, microorganisms, etc.), and has a long residence time in the atmosphere and a long transportation distance, so it has a greater impact on human health and atmospheric environmental quality.

Major hazards. Although fine particulate matter is only a small component of the Earth's atmosphere, it has important implications for air quality and visibility, among other things. Compared with coarser atmospheric particulate matter, fine particulate matter has a smaller particle size, is rich in a large number of toxic and harmful substances, and has a long residence time in the atmosphere and a long transportation distance, so it has a greater impact on human health and atmospheric environmental quality.

Studies have shown that the smaller the particles, the greater the harm to human health. Fine particulate matter can drift to a greater distance, so it has a large area of influence.

Fine particulate matter is more harmful to human health because the smaller the diameter, the deeper it enters the respiratory tract. Particulate matter with a diameter of 10 m is usually deposited in the upper respiratory tract, and particles below 2 m can penetrate deep into the bronchioles and alveoli. After fine particulate matter enters the alveoli of the human body, it directly affects the ventilation function of the lungs, making the body easy to be in a state of hypoxia.

In fact, everyone has not talked about this matter, the root cause is coal to gas heating, why do you say that, according to the history of winter in the northern region in the past, Beijing and other northern cities should be dry and cold air humidity in 20%-40%, and now it is (90%), so fog, to 80% is haze, deeper principle: due to the large water vapor content in the air, the particles in the air will absorb water and expand, the original small particles will become the present, the original may become PM10, Now the water vapor comes from the **, why didn't it in the past? Take a closer look around, and you will understand that natural gas will produce a lot of water after combustion, and it will be the same as a big steamer, can it not fog?

Some things can't be absolute, respect for science, you have to see two sides of things, even many aspects, I'm sure that after the heating period is over, Beijing will still be a blue sky. Agree with the support, I'm not an expert. Human flesh is welcome.

13.What is; hazards to human health; Experts explain how to defend against it; My country will soon be included in the monitoring criteria. (2 points per point).

14 (out of 3 points) Rich in a large number of harmful and toxic substances; Long residence time in the atmosphere and long transportation distance; It is not easy to be blocked, and after being inhaled into the human body, it will directly enter the bronchial tubes, interfere with the gas exchange in the lungs, and cause diseases including asthma, bronchitis and cardiovascular diseases; It can also be a vector for viruses and bacteria, contributing to the spread of respiratory infections. (Write three of the points, 1 point each, a total of 3 points).

15 (3 points in total) Categorize, compare, and list numbers. (Write two of these methods, 1 point).

Divided into categories, it clearly explains the different degrees of harm caused to the human body by particulate matter of different particle sizes in the air.

By comparison, haze weather caused by fine particulate matter is compared with sandstorms, highlighting the characteristics of haze weather that are more harmful to human health.

Column figures, with specific and accurate figures, to illustrate the different degrees of harm caused to human health by particles of different sizes. (Write down the effects of two of these methods, a total of 2 points).

16 (out of 4) (1) Using the method of analogy (or figurative rhetorical device), the person is compared to a moving "air filter", which vividly and easily explains the characteristics of a person who breathes a lot of air and filters it every day. The punctuated words reflect the vividness and scientificity of the expository language. (2 points in total).

2) "Mainly" is limited in terms of degree, and "one" is limited in terms of quantity. The punctuated phrase accurately illustrates that PM10 is one of the most important indicators to be monitored, but there are other indicators beyond that. The punctuated words reflect the accurate and scientific characteristics of the expository language.

2 points).

a. Fine particulate matter.

b. Particulate matter can enter the lungs.

c. Inhalable particulate matter.

d. Atmospheric particulate matter with an aerodynamic diameter of less than or equal to microns.

Answer: (b), ).

Europeans are white** Africans are black**, good luck is generally white face That is, full of European spirit, European emperor means lucky enough to burst Bad luck is African For example, if you are bald in the abyss, you can say that you are African,

Answer]: a, b, c

Refers to particulate matter in the atmosphere with a diameter of less than or equal to the digging-out micron, also known as particulate matter that can enter the lungs. Its diameter is less than 1 20 of the thickness of a human hair. Although it is only a small component of the Earth's atmospheric composition, it has important implications for air quality and visibility tolerance to dispersion.

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Answer]: a, b, c

PM2 5 is a particulate matter in the atmosphere with a diameter of less than or equal to 2 5 microns, also known as fine particulate matter. Its diameter is less than 1 20 of the thickness of a human hair. Although PM2 5 is only a very small component of the Earth's atmospheric composition, wax dust has a significant impact on air quality and visibility.