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.

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

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

For COSPAS-SARSAT system,（）usually transmit initial COSPAS-SARSAT alert.

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

All coast radio stations（）DSC installed for VHF and HF.

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

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

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.

As each MSI message will have a unique identity, the printing of messages already received correctly is（）.