Please use（）for（）.

（）by an ice-breaker, it is important to maintain a continuous listening watch on the appropriate VHF channel and to maintain a proper look-out for sound and visual signals.

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

What following is not among the function of SOLAS ships?（）

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.

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

In case a ship is in emergency or distress in any of 4 areas, it is required to use the continuous（）alert.

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.

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