Before counterflooding to correct a list，you must be sure the list is due to（）.

单项选择题At an angle of loll，the righting arm (GZ) is（）.

A.maximum
B.negative
C.positive，but reflexive
D.zero

单项选择题At an angle of loll，the capsizing moment is（）.

A.maximum
B.negative
C.positive
D.zero

单项选择题At all angles of inclination，the metacenter is（）.

A.vertically above the center of buoyancy
B.vertically above the center of gravity
C.at the intersection of the upright vertical centerline and the line of action of the buoyant force
D.at the geometric center of the underwater volume

单项选择题As a ship moves through the water，it causes a wake，which is also moving forward relative to the sea. In addition to a fore and aft motion，this wake also has a(n)（）.

A.downward and inward flow
B.downward and outward flow
C.upward and inward flow
D.upward and outward flow

单项选择题Angular motion about the vertical axis of a vessel is called（）.

A.yaw
B.surge
C.sway
D.roll