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