单选题All coast radio stations（）DSC installed for VHF and HF.A haveB hadC are havingD have had

Weather information is available from ______．

A.Commercial radio broadcasts

B.The Coast Guard on scheduled marine information broadcasts

C.VHF-FM continuous marine weather broadcasts provided by the National Weather Service

D.All of the above

下列哪种设备属于A级DSC终端_____。

A.MF DSC

B.NCT-60G DSC

C.VHF CH70 EPIRB

D.VHF DSC

Which radio equipment is not necessary for the ships sailing in the sea area A2?

A.MF DSC

B.VHF radio telephone

C.VHF DSC

D.VHF EPIRB

All VHF marine band radios operate in the simplex mode，which means that______．

A.only one person may talk at a time

B.only two persons may talk at the same time

C.the radio only transmits

D.the radio only receives

下列哪种设备属于C级DSC_____？

A.VHF CH70 EPIRB

B.HF DSC

C.MF DSC

D.VHF DSC

The damage to a vessel is over $25，000. Who must notify the nearest Coast Guard Marine Safety or Marine Inspection Office as soon as possible?

A.The Master of the vessel

B.The Radio Officer

C.The Chief Officer

D.All of the above