A.10 minutes every 4 hours
B.half an hour every other hour
C.irregular period of time
D.5 minutes every two hours
您可能感興趣的試卷
你可能感興趣的試題
A.in any INMARSAT regions
B.in each NAVTEX area
C.at any distance
D.in Areas A3 and A4
A.navigational / typhoon
B.traffic / meteorological
C.marine / hurricane
D.navigational / meteorological
A.dedicated system
B.MSI broadcasts
C.518KHZ
D.channel 16
A.ship’s movement
B.safety
C.ship’s management
D.hazards
A.by day or at night
B.almost round the clock
C.somewhat and sometime
D.from sunrise and sunset
最新試題
International Navtex service means the coordinated broadcast and automatic reception on（）khz of maritime safety information by narrow-band direct-printing telegraphy using English language.
Can MF/HF radiotelephone receive the MSI sent from the coast stations alone?（）
The frequency（）the safety message will be transmitted shall be included in DSC safety call.
Please use（）for（）.
Radio beacon can be activated（）in case of distress.
If the beacon is mounted at a wrong place, it may（）by sea water, chemicals, exhaust and vibrations.
On-scene communications will normally take place between（）.
Monitoring is especially important in a highly automated system which is dependent on careful（）procedure and format.
All coast radio stations（）DSC installed for VHF and HF.
SafetyNet is an international service for the broadcast and automatic reception of MSI by means of direct-printing through（）system.