单项选择题
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
It is possible for ships to receive safety message tran...
单项选择题It is possible for ships to receive safety message transmitted by Navtex station（）.
A.in any INMARSAT regions B.in each NAVTEX area C.at any distance D.in Areas A3 and A4
The frequency 518KHZ will be used to transmit（）and（）wan...
单项选择题The frequency 518KHZ will be used to transmit（）and（）wanings in NAVTEX.
A.navigational / typhoon B.traffic / meteorological C.marine / hurricane D.navigational / meteorological
