（）is used for measuring horizontal and vertical angles.

单项选择题（）means rudder to be held in the force and aft angles.

A.Steady
B.Meet her
C.Midships
D.Stop engines

单项选择题（）means check the swing of the vessel’s head in a turn.

A.Steady
B.Meet her
C.Midships
D.Stop engines

单项选择题1 nautical mile is the lenth of an arc of a great circle which subtends an angel of（）at the center of the Earth.

A.1degree
B.1 minute
C.1second
D.1.5 degree

单项选择题A ship is side to be（）when the whole ship moves bodily to port and then to starboard.

A.rolling
B.pitching
C.heaving
D.swaying

单项选择题A ship is side to be（）when the bow and stern rise and fall with the oncoming waves.

A.rolling
B.pitching
C.heaving
D.swaying