A.promote
B.improve
C.guarantee
D.both A and B
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A.taking the place of the radio system
B.introducing a new life-saving system
C.saving the vessels in distress
D.improving the communication on land
A.was suffering
B.is suffering
C.has suffered
D.has been suffering
最新試題
The advantage of geostationary satellites is（）.
Every lifeboat which is fitted with a fixed two-way（）radiotelephone apparatus with an antenna which is separately mounted shall be provided with arrangements for sitting and securing the antenna effectively in its operating position.
Before GMDSS, if the radio officer on board is serious ill,（）.
For COSPAS-SARSAT system,（）usually transmit initial COSPAS-SARSAT alert.
The frequency（）the safety message will be transmitted shall be included in DSC safety call.