The services provided by airlines can be divided into three distinct categories: scheduled services, charter services and _________.
A、“frequent” programs
B、air taxi services
C、executive aircraft
D、extra free travel
【正确答案】：B
【题目解析】：(P123)航空公司提供的服务可以分为三种不同的类别：定期客运服务；包机服务；出租飞机（短途小飞机）服务。
