说明：  飞机订票系统 　　录入： 　　可以录入航班情况（数据可以存储在一个数据文件中，数据结构、具体数据自定） 　　查询： 　　可以查询某个航线的情况（如，输入航班号，查询起降时间，起飞抵达城市，航班票价，票价折扣，确定航班是否满仓）； 　　可以输入起飞抵达城市，查询飞机航班情况； 　　订票：（订票情况可以存在一个数据文件中，结构自己设定） 　　可以订票，如果该航班已经无票，可以提供相关可选择航班； 　　退票： 可退票，退票后修改相关数据文件
(Aircraft booking system (limited to 1 completed) Tasks: The system can be achieved through the following functions: Entry: Can be input flight conditions (data can be stored in a data file, data structure, specific data from set) Inquiries: Can query a particular route (such as, enter the flight number, check arrival and departure times, arrival departure city, flight fares, fare discounts, to determine whether the full flight position) Can enter the take-off on arrival, check flight situation Booking: (booking conditions can exist in a data file, structure their own set) Could be booking, if the flight has been without a ticket, you can provide alternative flights Refund: You can refund, a refund after the revision of relevant data files )