What does "in-flight service" ( Line 1, Para, 5 ) mean
[A] Service on the plane. [C] Flights within one country.
[B] A new safety device. [D] Charge-free air service.

A．What does "in-flight service" ( Line 1, Para, 5 ) mean
B．Service on the plane.
C．A new safety device.
D．Flights within one country.
E．Charge-free air service.