单项选择题
Lines passed around the falls to hold the boat while passengers are boarding are（）.
A.life lines B.frapping lines C.tricing lines D.tripping lines
单项选择题 Life preservers should be stowed in（）.
单项选择题 Life jackets should be marked with the（）.
单项选择题 Instructions to the crew in the use of all the ship’s lifesaving equipment shall be completed（）.
