Cần phải đeo khẩu trang trong những trường hợp nào? Bạn bắt buộc phải đeo khẩu trang trong mọi trường
During the Covid-19 pandemic, you can reuse your mask: between uses it only needs to be stored in a paper envelope for 1 week. That is so short compared with how long corona virus takes (upwards of 8 hours) before it starts no longer working properly.
The ability of an environmental mask to reduce the negative effects of air pollution depends on the type of pollutant, the type of respirator you are using and how to use it.
Europe and many countries have gradually removed the lockdown, and many people have realized the importance of wearing a mask to prevent the corona virus.
We have studied the effects of Lockdown in coronavirus-affected countries.