A.SOS sent three times
B.ten one-second dashes with a four-second interval between them
C.twelve four-second dashes with a one-second interval between them
D.twelve one-second dashes with a short interval between them
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A.1.5 and greater
B.1.25 and greater
C.1.0 and greater
D.0.5 and greater
A.hold anchor
B.leave anchor
C.let go anchor
D.weigh anchor
A.reduce the length of the cable
B.pay out more anchor cable
C.back the engines
D.swing the rudder several times to work the anchor into the bottom
A.Distress
B.Safety
C.All clear
D.Urgency
A.a ship is threatened by grave and imminent danger and requests immediate assistance
B.a calling station has an urgent message about the safety of a person
C.the message following the prefix will be about the safety of navigation
D.the message following is a meteorological warning
最新試題
To reduce mild fever the MOST useful drug is（）.
What happens to the efficiency of an anchor when it is moved from sand to mud?（）
The towing light is a(n)（）.
The transmission of messages respecting the dangers specified is free（）cost to the ships concerned.
To prevent a wooden hull from leaking you caulk it（）.
There is plenty of（）at this area.
The best method to stop a vessel from dragging anchor in a sand bottom is to（）.
The expression DROP ANCHOR means（）.
Which is NOT a distress signal?（）
There is not（）depth of water around the area centered at the lighthouse.