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（）.

The advantage of geostationary satellites is（）.

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

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

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

Stations in the United States of America are grouped by states arranged in the alphabetical order of their（）.

Radio beacon can be activated（）in case of distress.

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

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