For example, from four kilometers to the university town, you can directly buy a ticket for the university town on line 1 at the four-kilometer station, get on the bus at four kilometers, and leave the station within the specified time, so that you can stop "buying tickets and transferring" on the way, and immediately turn around and return to the university town even if you sit too far. If you only buy a ticket at the transfer station when you leave, you can buy another ticket without leaving the station. You can transfer directly to the university town at the station, but when you leave the station, you can directly ask the station attendant to make up the ticket and make up the difference.