2. Healthy people wear masks to protect susceptible people.
3. Wearing a mask is to cut off the route of transmission.
4、? There are three situations, depending on the situation.
A source of infection refers to a person or an animal that can spread pathogens. Patients, carriers or suspected patients are the source of infection, so wearing a mask is equivalent to isolating the source of infection, so the source of infection is controlled.
Extended data:
Wearing a mask, I personally feel that no matter who wears it, it is a way to block the entry and exit of respiratory viruses, that is, to cut off the route of transmission. Not only wearing a mask, but also cutting off the way includes strong measures such as sealing, isolation, no gathering and avoiding contact.
Protecting susceptible people is a "one-stop", that is, asking our students to remember "don't touch the source of infection, exercise and get vaccinated". I deeply agree with the latter two, but I strongly disagree that "don't touch the source of infection" is to protect susceptible people, because avoiding it can't solve the problem. Only by staying with you when danger comes can we really protect you, that is, exercise and vaccination can we improve our immunity.