单项选择题
Mariners should ensure correct（）of aids to navigation during twilight periods when some lighted aids to navigation are lit while others are not.
A.identification B.distinction C.discrimination D.clearly seeing
单项选择题 If the winch should fail while you are hauling in the anchor，what prevents the anchor cable from running out（）.
单项选择题 If the ship is alongside the wharf，what kind of（）is used?
单项选择题 If a ship has sternway，with accommodation block aft，she may settle with the wind（）.
