When you buy masks recently, you will find that KN95 masks/N95 masks are divided into two types: with or without breathing valve and without breathing valve. Why do masks have breathing valves? If mask wearers, people with chronic respiratory diseases, heart diseases or other diseases accompanied by... read more
The source of the coronavirus can be traced back to 8000 BC at the latest. It may also be 8100 BC. Non-cold-blooded flying animals, bats and birds seem to be the best hosts for coronaviruses (bats carry A and B coronaviruses; birds carry C and D coronaviruses). In the early 1970s, it was confirmed t... read more
The orthocoronavirus subfamily (scientific name: Orthocoronavirinae), commonly known as coronavirus, is a type of zoonotic single-stranded RNA virus that spreads between animals and humans. Coronavirus can infect mammals and birds, causing digestive tract diseases in cattle and pigs or upper respira... read more
Dust masks are indispensable protective equipment for workers engaged in and exposed to dust. They are mainly used in working environments that contain low concentrations of harmful gases and vapors. Only adsorbent or sorbent is installed in the filter box. Some filter boxes are also equipped with a... read more
Dust masks are indispensable protective equipment for workers engaged in and exposed to dust. They are mainly used in working environments with low concentrations of harmful gases and vapors. Only adsorbent or sorbent is installed in the filter box. Some filter boxes are also equipped with a filter ... read more
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