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

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

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

By using（）system a ship can send a distress message and know with certainty it will be received.

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

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.

The frequency（）the safety message will be transmitted shall be included in DSC safety call.

The advantage of geostationary satellites is（）.

COSPAS-SARSAT is intended to be used for（）.

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