The COSPAS-SARSAT 406mhz system was adopted as an element of the GMDSS by IMO in（）.

单项选择题which function is the most important one of the GMDSS.（）

A.alerting
B.on-scene communication
C.safety information
D.general communication

单项选择题The quality of EGC message is（）affected by the position of the ship, the time of reception and climatic condition.

A.sometimes
B.all times
C.never
D.partly

单项选择题The information flow of the MSI broadcast must be controlled（）.

A.to avoid mutual interference
B.to keep silence
C.owing to the time-share nature
D.to regulate transmitter power

单项选择题If EGC receiver shares a same antenna with INMARSAT MES, it means that it can receive MSI（）.

A.from any INMARSAT satellite
B.via any appropriate Navtex and EGC station
C.via the satellite the MES is tracking
D.from any RCC and coast station

单项选择题EGC safetyNet transmits（）types of messages for mariners.

A.four
B.six
C.five
D.three