单项选择题
A.Icebergs may travel in a direction many degrees different from the sea ice
B.Both icebergs and sea ice will move in approximately the same direction and at the same speed
C.Icebergs and sea ice will move in the same direction，but at different speeds due to the sail effect of the berg
D.Icebergs and sea ice will move in the same direction，but the iceberg will move slower because of its underwater bulk
单项选择题 Two vessels are abreast of each other and passing port to port in a confined waterway. What should you expect as your bow approaches the screws of the other vessel? （）
单项选择题 Topside icing that blocks freeing ports and scuppers（）.
单项选择题 Topside icing decreases vessel stability becauseit increases（）.