A.have
B.had
C.are having
D.have had
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A.repairs
B.repairing
C.repaired
D.being repaired
A.which is assisted
B.that assist you
C.when you assisted
D.when being assisting
A.the range of antenna can cover everywhere in the world
B.we can know the ship’s exact position
C.that the distress alert can be located as soon as possible
D.antenna of permanent earth stations may be directed towards fixed points in the sky
A.which
B.on which
C.at which
D.in which
A.it necessary
B.it is necessary
C.it necessary to
D.necessary
最新試題
International Navtex service means the coordinated broadcast and automatic reception on（）khz of maritime safety information by narrow-band direct-printing telegraphy using English language.
Every lifeboat which is fitted with a fixed two-way vhf radiotelephone apparatus with（）which is separately mounted shall be provided with arrangements for sitting and securing the antenna effectively in its operating position.
Stations in the United States of America are grouped by states arranged in the alphabetical order of their（）.
The frequency（）the safety message will be transmitted shall be included in DSC safety call.
Radio communication（）for many years and helps to save tens of thousands of lives.
The vessel has stayed in port for seven days because she needs（）.
What following is not among the function of SOLAS ships?（）
Ship-to-ship distress alerting should be conducted by（）.
（）by an ice-breaker, it is important to maintain a continuous listening watch on the appropriate VHF channel and to maintain a proper look-out for sound and visual signals.
Can MF/HF radiotelephone receive the MSI sent from the coast stations alone?（）