Distress traffic is the communication（）between the station in distress and the ships, aircraft, coast radio stations, coast earth stations and rescue centers participating in the rescue work.

Please use（）for（）.

The priority of EGC messages is classified by（）.

（）by an ice-breaker, it is important to maintain a continuous listening watch on the appropriate VHF channel and to maintain a proper look-out for sound and visual signals.

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.

The advantage of geostationary satellites is（）.

The quality of EGC messages is（）affected by the position of the ship, the time of reception and climatic conditions.

The frequency（）the safety message will be transmitted shall be included in DSC safety call.

By using（）system a ship can send a distress message and know with certainty it will be received.

Particular care should be（）in selecting CESs in areas where Ocean Regions overlap.