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.

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

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.

（）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.

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