单项选择题
A.are seated with seat belts on and doors shut
B.are seated with seat belts on and doors open
C.are to shift to one side to right it
D.escape from the craft
单项选择题 A lifeboat is weight tested by lowering to near the waterand loading to capacity with weight evenly distributed. Itis then lowered into the water and released. This test mustbe done at least once every（）.
单项选择题 A fully loaded motor-propelled lifeboat must be capable of attaining a speed of at least（）.
单项选择题 A certificated lifeboatman assigned to command the lifeboat should（）.