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

SafetyNet is an international service for the broadcast and automatic reception of MSI by means of direct-printing through（）system.

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.

Radiotelephony communication or radio telex communication or both will be carried out by terrestrial or satellite means,（）the equipment fitted on ship and the area in which the incident occurs.

At least two two-way VHF radiotelephone apparatus shall be provided on every cargo ship of（）tons gross tonnage and upwards but less than 500 tons gross tonnage.

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

Can MF/HF radiotelephone receive the MSI sent from the coast stations alone?（）

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.

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

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