The rescue coordination center may（）on stations which interfere with traffic.

If the beacon is mounted at a wrong place, it may（）by sea water, chemicals, exhaust and vibrations.

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.

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

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

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

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

Monitoring is especially important in a highly automated system which is dependent on careful（）procedure and format.

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

The priority of EGC messages is classified by（）.