If COVID-19-infected people appear in some areas outside Beijing, or are classified as middle-high risk areas, or have gone abroad for 2 1 day, then according to Beijing's policy of returning to Beijing, people from these areas need to postpone their return to Beijing. Based on big data, these people usually can't buy tickets to Beijing, including high-speed rail tickets and air tickets, even if their health treasures are normal. This situation is basically impossible to appeal, and you can only return to Beijing after the local risk is reduced to low or the exit record is 2 1 day.