A.Their bearing is almost constant，even when the true bearing of the contact changes appreciably
B.They always appear on a bearing of 90°From the true bearing of the contact
C.The indirect echoes usually appear in shadow sectors
D.When plotted，their movements are usually abnormal
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A.sound signal
B.light signal
C.visual signal
D.radiotelephone
A.icebreaker support is finished
B.icebreaker support is commencing
C.the icebreaker is icebound
D.the icebreaker is beset
A.I am altering my course to starboard
B.I am altering my course to port
C.I am operating astern propulsion
D.My vessel is stopped and making no way through the water
A.Bruce anchor
B.Dunn anchor
C.Hook anchor
D.Danforth anchor
A.naphtha，vm and p
B.tridecanol
C.cottonseed oil
D.camphor oil
最新試題
An engine compartment gasoline fire requires which type of extinguisher?（）
An indirect radar echo is caused by a reflection of the main lobe of the radar beam off the observer’s vessel. Which of the following is NOT a characteristic of indirect echoes? （）
All personnel on board a vessel should be familiar with the rescue boat’s（）.
Air circulation is caused or affected by（）.
An advantage of the Christmas Tree towing method is to（）.
An “on-load” release system on a survival craft means the cable can be released（）.
An “atoll cloud” forming over an island due to heating of the land during the daytime would be which type? （）
Aids to navigation marking the intracoastal waterway can be identified by（）.
An all-round flashing yellow light may be exhibited by a(n)（）.
An icebreaker displaying a flag hoist which consists of the code letters “WO” (Whiskey Oscar) is indicating that（）.