单项选择题
A certificated lifeboatman assigned to command the lifeboat must（）.
A.be the first individual to board the craft B.drain the hydraulic pressure before lowering the craft C.have a list of the persons assigned to the lifeboat D.All of the above
单项选择题 A chain stripper is used to（）.
单项选择题 A check line is（）.
单项选择题 A chock（）.
