单项选择题
A.from any Inmarsat satellite
B.from any appropriate Navtex and EGC station
C.via the satellite the SES is tracking
D.from any RCC and coast station
单项选择题 The receiving stations can use the B2 character to（）different, classes of messages.
单项选择题 Navtex transmitter identification character（）is used to identify the broadcasts which are to be accepted by the receiver and those are to be rejected.
单项选择题 The difference between international and national Navtex Service is limited to（）.