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.

COSPAS-SARSAT is intended to be used for（）.

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.

We consider（）send a helicopter with medical facilities to the distress area.

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

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

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.

（）will form the basis for distress alerting and safety calling.

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