单项选择题
A.international NAVTEX Service B.FleetNET Service C.SafetyNet Service D.WWNWS
All NAVTEX messages（）owing to their nature of importanc...
单项选择题All NAVTEX messages（）owing to their nature of importance.
A.can suppress B.can be suppressed C.can not be suppressed D.are to be suppressed
The difference between international and national Navte...
单项选择题The difference between international and national Navtex Service is limited to（）.
A.frequency allocated B.both language and frequency C.language used D.transmission power and time
A Navtex station in each NAVAREA is usually allowed to ...
单项选择题A Navtex station in each NAVAREA is usually allowed to have（）for transmission.
A.10 minutes every 4 hours B.half an hour every other hour C.irregular period of time D.5 minutes every two hours
