单项选择题
A.anywhere in the world B.at sea C.in the air D.ashore
The COSPAS-SARSAT 406mhz system was adopted as an eleme...
单项选择题The COSPAS-SARSAT 406mhz system was adopted as an element of the GMDSS by IMO in（）.
A.1982 B.1980 C.1984 D.1988
which function is the most important one of the GMDSS.（...
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
The quality of EGC message is（）affected by the position...
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
