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 vessel has stayed in port for seven days because she needs（）.

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

（）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.

SOLAS ships shall be equipped with（）.

Radio communication（）for many years and helps to save tens of thousands of lives.

Ship-to-ship distress alerting should be conducted by（）.

Every lifeboat which is fitted with a fixed two-way vhf radiotelephone apparatus with（）which is separately mounted shall be provided with arrangements for sitting and securing the antenna effectively in its operating position.

Before GMDSS, if the radio officer on board is serious ill,（）.

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.