单项选择题
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
Distress alerts will be relayed on the（）when the RCC co...
单项选择题Distress alerts will be relayed on the（）when the RCC considers it necessary.
A.dedicated system B.MSI broadcasts C.518KHZ D.channel 16
