单项选择题
（） must know the location as well as the operation of the life-saving and fire-fighting appliances.
A. All officers B. All engineers C. All the crew D. All sailors
单项选择题 （）should be saved first in an accident.
单项选择题 The emergency alarm is sounded on （）according to master’s order.
单项选择题 The life-jacket is usually put （）in your cabin.
