C.Second Class Radio Electronic Certificate D.First Class Radio Electronic Centificate 选A

73.Thermal printing paper,used in many NAVTEX receivers should be protected from______ A.Radiated frequency B.Audio frequency C.Magnetic flux D.Light 选D

74.In the COSPAS-SARSAT,satellite EPIRBs function on the frequencies of______ A.CH70/243MHz B.406/121.5MHz

C.121.5/243MHz D.406/1.6GHz 选B

75.Radio stations which hear transmissions concerning the safety of navigation shall listen to the transmission______ A.when they are sure that there is not distress traffic B.as soon as they hear a distress message

C.until they are certain that it does not concern them D.which station is sending the distress message 选A

76.What is the total voltage and capacity of two 12V batteries coupled in series if each battery has capacity of 100Ah? A.12V 100Ah B.24V 100Ah

C.12V 200Ah D.24V 200Ah 选B

77.Ships in area A2 will at least transmit a ship-to-shore alert on______and satellite EPIRB A.2182kHz B.2174.5kHz C.2187.5kHz D.156.8MHz 选C

78.______is a station in the mobile service,which is used in distress and which transmits signals to facilities SAR operation,and which is not used 9GHz frequency band A.SART

B.EIPRB C.DSC D.GPS 选B

79.The satellite communication requirements of chapter______of the 1974 SOLAS Convention can be met,either wholly or in part,by INMARSAT MESs capable of two-way communications,such as INMARSAT-A or INMARSAT-B and INMARSAT-C A.V B.III C.IV D.II 选C

80.In NAVTEX service,local warnings are normally breadcast on______

A.NAVTEX service B.SafetyNET service C.VHF voice only D.MF/HF telephone 选A

81.COSPAS-ARSAT is primarily used for______ A.improving communications in polar regions B.providing MSI to mobile sations

C.saving the system users in distress anywhere in the World D.transmitting and receiving infoumation 选C

82.There are______NAVAREAs designated by IMO all over the world A.13 B.4