单项选择题
SafetyNet is an international service for the broadcast and automatic reception of MSI by means of direct-printing through（）system.
A.DSC B.EPIRB C.EGC D.NBDP
单项选择题 Ship-to-ship distress alerting should be conducted by（）.
单项选择题 On-scene communications will normally take place between（）.
单项选择题 （）will form the basis for distress alerting and safety calling.
