Changchun back to Baishan big data can not be checked. Communication big data itinerary card can show all the countries (regions) visited by the user in the past 14 days and domestic cities where the stay is more than 4 hours, as long as there is no stay of 4 hours will not be checked. Changchun, the ancient name of Xidu, tea ah Chong, Jilin Province, the jurisdiction of prefecture-level cities, provincial capitals, sub-provincial cities, Type I large cities, the core city of the Ha-Chang urban agglomeration.