2. At least seven people have said that I gained weight during the New Year, but China has a population of 654.38+04 billion. In contrast, these seven people are just a drop in the ocean and can be completely ignored, so I am not fat.
3. The subscriber you dialed is social security, please dial again in your next life.
Grandpa is hard of hearing and wears a mask to the streets in winter.
The dust blocking efficiency of the mask is based on its blocking efficiency for fine dust, especially for inhalable dust below 2.5 microns. Because dust with this particle size can directly enter alveoli, it has the greatest impact on human health. Gauze mask, its dustproof principle is mechanical filtration, that is, when dust collides with gauze, some large particles of dust in abrasive cloth will be blocked by layers of barriers. For some fine dust, especially dust smaller than 2.5 microns, it will enter the respiratory system through the mesh of gauze. Dust mask, its filter material is composed of activated carbon fiber felt pad or non-woven fabric, and those inhalable dust smaller than 2.5 microns pass through this filter material.