Second: closed management, only students. School staff, teachers, tour guides, delivery personnel, etc. You can still get in and out of school, or they may have brought the virus. Schools are crowded places, and once someone is infected, it will spread on a large scale. Third: For example, my sister is in college now, and she has been in a closed management state from freshman to sophomore next semester. However, it is not completely closed management. Students who take leave or have something to do can still leave school with the consent of the counselor. This also creates another way of transmission.
I think it is the physical quality of students now. Nowadays, many students do not exercise in the dormitory for a day, and their antiviral ability and physical fitness are not very good. Although it has been closed for management, vendors outside the school will still sell snacks, and we college students also like to eat these snacks, and we can also bring food in through the fence, which makes it possible for the virus to flow into the school; Closed management only closes students, other staff, teachers, distribution personnel, etc. You can go in and out of school, or you may carry a virus; Epidemic prevention and control is a long-term matter, or in the next five years, 65438+20 years will not end.