单项选择题
If the DSC controller is configured for MF/HF operation, the distress will be sent on（）.
A.double frequencies B.single frequency C.dedicated frequency D.multiple frequencies
单项选择题 Ship-to-ship distress alerting should be conducted by（）.
单项选择题 If a DSC distress relay is transmitted from coast station , it will（）.
单项选择题 EGC is a（）part of INMARSAT-C.
