Because if you go to the middle and high risk area and change stations, if there is a 24-hour or 48-hour nucleic acid certificate, the station will open another transfer channel, and try to transfer from point to point and complete it in one line.
Just listen to the arrangement of the staff. If there are no measures at the station, then you can transfer normally.
If you go from a low-risk area to a medium-high-risk area, the short-term stopover will not be isolated. As long as it does not exceed 4 hours, the health code will not change color, but the travel card may be marked with "*". Once the "*" is found on the travel card, the nucleic acid will be tested first after arriving at the destination.
The travel card "*" does not mean that the user has actually been to the middle and high risk area, but only means that the city where the user has visited has the middle and high risk area. If there is no contact case or close contact, but the travel card is "*", "three days and two inspections" should be implemented after arriving at the destination.