The difference between the forward and aft drafts is（）.

单项选择题The center of flotation of a vessel is the point in the waterplane（）.

A.about which the vessel lists and trims
B.which coincides with the center of buoyancy
C.which，in the absence of external forces，is always vertically aligned with the center of gravity
D.which is shown in the hydrostatic tables as VCB

单项选择题The angular motion of a ship in the athwartship is termed（）.

A.pitching
B.yawing
C.rolling
D.tracking

单项选择题That center around which a vessel trims is called the（）.

A.tipping center
B.center of buoyancy
C.center of gravity
D.turning center

单项选择题Semisubmersibles A and B are identical. However，A is more tender than B. This means that A relative to B has a（）.

A.lower KG
B.smaller GM
C.smaller roll angle
D.larger GZ

单项选择题Progressive flooding may be indicated by（）.

A.ballast control alarms
B.excessive draft
C.excessive list or trim
D.a continual worsening of list or trim