Ordinary people who want to strengthen their immunity should do the following: (1) Do more physical exercise to enhance physical fitness and strengthen immunity. (2) Avoid the decline of physical resistance, reasonable rest, do not stay up late, do not overwork. (3) Have a reasonable diet, balanced nutrition, and do not eat in a partial manner, do not smoke, and do not abuse alcohol. If you want to have effective protection, you should do the following: (1) Whether you cough, sneeze or have a runny nose, cover it with paper or handkerchief. (2) Keep a distance of more than 1 meter when people are in contact with each other. (3) Avoid going to crowded places as much as possible and keep indoor ventilation. (4) Wear a mask with protective function when you go out.