航空器必须在指定的无线电频率上与空中交通管制部门联络并接受管制。

A、AllaircraftshallestablishcontactwiththeATCdepartmentontheappointedradiofrequenciesandacceptitscontrol

B、AllaircraftshallestablishcontactwiththeATCdepartmentintheappointedradiofrequenciesandacceptitscontrol

C、AllaircraftshallestablishcontactwiththeATCdepartmentontheassignedradiofrequenciesandacceptitscontrol

D、AllaircraftshallestablishcontactwiththeATCdepartmentintheassignedradiofrequenciesandacceptitscontrol

正确答案：C