C.16 D.12 选C

83.An area within the coverage of INMARSAT satellite in which continuous distress alerting is available is______,excluding area A1 and A2

Asea area A3 B.sea area A2 C.distress area D.GMDSS areas 选A

84.The quality of EGC message is_______affected by the position of the ship,the time of reception and climate conditions A.sometimes

B.all times C.never D.partly 选C

85.How many MF frequencies are available for DSC distress-related calls? A.One B.Two C.Four D.Five 选A

86.Ships at sea are in urgent need of MSI because they are______various kinds of hanger A.subject for

B.liable to C.easy to meet D.always encounter 选C

87.What frequencies are used for receiving HF MSI?

A.HF MSI is transmitted on a primary frequency of 518KHZ and a secondary frequency of 490kHz

B.HF MSI is transmitted on 8414.5kHz pius one other(undesignated)HF frequency

C.HF MSI is transmitted on the third ITU channel in each HF band(2,4,6,8,12,16 and 22MHz)

D.HF MSI is transmitted on certain dedicated frequencies 选D

88.Which statement is false regarding the transmission of maritime safety

information?

A.In the mainland of China,518kHz and 490kHz frequencies are used in NAVTEX services

B.In Taiwan province of China,518kHz and 490kHz frequencies are used in NAVTEX services

C.518kHz,4209.5kHz AND 490kHz are all NAVTEX frequencies D.The

frequencies

4210kHz,6114kHz,8416.5kHz,12579kHz,16806.5kHz,22176kHz 26100.5kHz are not used in NAVTEX services 选A

89.In INMARSAT system,each LES provides,as a minimum,______ A.telephone B.telephone and telex C.telephone,telex and facsimile D.telephone,telex and facsimile and data

of and

选D

90.The following radio communication systems are used in GMDSS except the INMARSAT system_______ A. VHF

B. VHF MF and HF terrestrial systems C. the COSPAS-ASRSAT systems D. the FLAG SINGAL system 选D

91. Which of the following statement is ture ? A. NAVTEX stations have the transmission power B. NAVTEX stations can transmit at the same time

C. every NAVTEX stations have the different identification charactern in each NAVTEX

D. There are 24 NAVTEX stations in each NAVTEX