單項選擇題Small floes of rough，hummocky sea ice capable of damaging a vessel（）.

A.can usually be detected by radar in a smooth sea at a range of 4 to 6 kilometers
B.are indistinguishable from sea return on the PPI
C.are invisible to radar when covered with a thick layer of snow
D.are usually seen at night before they are close enough to provide a radar echo


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1.單項選擇題On a twin-screw，twin-rudder vessel，the most effective way to turn in your own water，with no way on，is to put（）.

A.one engine ahead and one engine astern，with full rudder
B.one engine ahead and one engine astern，with rudders amidships
C.both engines ahead，with full rudder
D.both engines astern，with full rudder

2.單項選擇題On a single-screw vessel the stern frame（）.

A.furnishes support to the rudder，propeller shaft，and transom frame
B.provides foundations for after mooring winches
C.provides foundations for the main propulsion engines
D.transfers the driving force of the propeller to the hull

3.單項選擇題In selecting a tug for moving a vessel，consideration should be given to its（）.

A.indicated horsepower，bollard pull，and displacement
B.indicated horsepower，maneuverability，and displacement
C.indicated horsepower，bollard pull，and maneuverability
D.bollard pull，displacement，and maneuverability

4.單項選擇題In order to reduce your wake in a narrow channel you should（）.

A.apply enough rudder to counter the effect of the current
B.change your course to a zigzag course
C.reduce your speed
D.shift the weight to the stern

5.單項選擇題In most cases，when a large merchant vessel enters shallow water at high speed the（）.

A.maneuverability will increase
B.speed will increase
C.bow will squat farther than the stern
D.vessel will rise slightly，on a level plane