What does "three cases and nine systems" mean?

Legal analysis: three cases, namely, school work plan, school emergency plan for public health emergencies, and emergency psychological intervention plan; The "nine systems" are the infectious disease epidemic reporting system, the morning and afternoon inspection system for teachers and students, the registration and tracking system for students' absence due to illness, the resumption inspection system, the health management system for teachers and students, the vaccination certificate inspection system, the ventilation and disinfection system, the environmental sanitation inspection notification system, and the management system for foreign personnel entering the park.

Legal basis: "Establish' three cases and nine systems' to ensure the physical and mental health of teachers and students" and formulate emergency plans for public health emergencies in schools, school work plans and psychological intervention plans for emergencies. Establish the "three cases and nine systems" such as the morning and afternoon inspection system for faculty and students, the health inspection system, the reporting system for infectious diseases and public health emergencies in schools, the registration system for absenteeism due to illness and the tracing reporting system for reasons, the inspection system for resumption of classes, the health management system for teachers and students, and the management system for personnel entry and exit. Disinfection and cleaning system, infectious disease isolation system, environmental health inspection notification system, the formation of education and health authorities, disease control, health supervision institutions, community health service centers, medical care.