单项选择题
The difference between the forward and aft drafts is（）.
A.list B.heel C.trim D.flotation
单项选择题 The center of flotation of a vessel is the point in the waterplane（）.
单项选择题 The angular motion of a ship in the athwartship is termed（）.
单项选择题 That center around which a vessel trims is called the（）.
