航海英语单项选择题每日一练(2019.12.16)

单项选择题
Initial stability of a vessel may be improved by（）.
A.removing loose water
B.adding weight low in the vessel
C.closing crossover valves between partly filled double bottom tanks
D.All of the above
单项选择题
A special daymark is a（）.
A.red-and-white octagon
B.daymark with a yellow stripe on it
C.green square
D.yellow diamond
单项选择题
A cable used by helicopters for lifting or lowering persons in a pick-up operation is a（）.
A.Hoist
B.Rope
C.Cable
D.Line
单项选择题
That center around which a vessel trims is called the（）.
A.tipping center
B.center of buoyancy
C.center of gravity
D.turning center
单项选择题
A wooden plug fitted tightly in the vent of a damaged tank may prevent the tank from（）.
A.filling completely
B.developing free surface
C.developing free surface moment
D.collapsing