If no one returns the ticket, the standby can't buy the ticket and can't take the train. The standby can't get on the bus without a refund, because the standby is another way to buy tickets. Once someone refunds or changes his ticket, the ticket can be given priority to the waiting crowd. Failure to buy a ticket means that you can't get on the bus without a ticket. If the standby ticket purchase is unsuccessful, you can only buy tickets for other trains at other times or change the means of transportation. If the standby does not refund the ticket, it will not become empty, and you can't take the train or high-speed rail on the same day. Standby means that someone needs to refund your ticket and will give you a chance to successfully purchase the ticket when you arrive. When the standby ticket is grabbed, the system will make up the ticket according to the order submitted by the customer. Generally, people in front will get tickets first, first come, first served. When purchasing tickets, once you find that you can't buy them, you need to use the ticketing service in time. So you can take the train.