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

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

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.

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

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

Every ship constructed on or after（）shall comply with all the applicable requirements of this chapter.

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

（）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.

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

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