卫生部也表示，全国有足够的N95口罩，国人不必争买囤货。Guardian、Unity、 Cold Storage和Giant等大型零售商和药房都有出售N95口罩。
一盒20个的3M N95口罩价格是多少？$25? $35? 能宣布它的价格以杜绝那些卖每个超过4元的情况出现吗？
Atmospheric particulate matter – also known as particulates or particulate matter (PM) – are tiny pieces of solid or liquid matter associated with the Earth’s atmosphere. They are suspended in the atmosphere as atmospheric aerosol, a term which refers to the particulate/air mixture, as opposed to the particulate matter alone. However, it is common to use the term aerosol to refer to the particulate component alone.
Sources of particulate matter can be man made or natural. They can adversely affect human health and also have impacts on climate and precipitation. Subtypes of atmospheric particle matter include suspended particulate matter (SPM), respirable suspended particle (RSP; particles with diameter of 10 micrometres or less), fine particles (diameter of 2.5 micrometres or less.