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.
The rescue coordination center may（）on stations which interfere with traffic.
All coast radio stations（）DSC installed for VHF and HF.
Radio beacon can be activated（）in case of distress.
Stations in the United States of America are grouped by states arranged in the alphabetical order of their（）.
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.
By using（）system a ship can send a distress message and know with certainty it will be received.
We consider（）send a helicopter with medical facilities to the distress area.
SafetyNet is an international service for the broadcast and automatic reception of MSI by means of direct-printing through（）system.
SOLAS ships shall be equipped with（）.