A radio link between a transmitting earth station and a receiving earth station through one satellite is named a（）.

A.a terrestrial MF system
B.a satellite communication system
C.a land HF radio system
D.a coastal VHF system

A.Russian
B.French
C.English
D.German

A.transmit distress signal
B.send response signal
C.transmit the signal of ship‟s position
D.be start by X-band radar