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

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

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

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

At least two two-way VHF radiotelephone apparatus shall be provided on every cargo ship of（）tons gross tonnage and upwards but less than 500 tons gross tonnage.

The advantage of geostationary satellites is（）.

The quality of EGC messages is（）affected by the position of the ship, the time of reception and climatic conditions.

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

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

Can MF/HF radiotelephone receive the MSI sent from the coast stations alone?（）