（）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.

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.

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

The rescue coordination center may（）on stations which interfere with traffic.

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