Relying on data aggregated from the state and various departments and districts, the risk statuses of green, orange, and red are measured after analyzing and evaluating the prevention and control rules and data modeling. In addition, foreigners are required to upload a photo of their identity document at the time of application as well as a photo of them together while holding the identity document, which can be processed according to the normal procedure after the system has reviewed the application.

Taking public **** transportation. Like buying airplane tickets, train tickets and so on have a record ah, if you have a confirmed case in the same compartment or on the same flight, it may be judged as a close contact, the relevant departments will investigate your status and trajectory, so as not to cause the spread of the epidemic.