属于金属保护层的有黑铁皮、( )、聚氯乙烯复合钢板和不锈钢板等。

A．油毡

B．镀锌铁皮

C．铅皮

D．石棉水泥浆

A vessel aground may have negative GM since the（）.

A.decrease in KM is equal to the loss of draft

B.virtual rise of G is directly proportional to the remaining draft

C.lost buoyancy method is used to calculate KM, and KB is reduced

D.displa ement lost acts at the point where the ship is aground