单项选择题
A.darkness
B.daylight
C.simulated engine-room
D.all of the above
单项选择题 The main causes of fire on board ships are （）
单项选择题 The basic training in fire prevention and fire fighting should include the theoretical elements which should cover （）.
单项选择题 The basic training in fire prevention and fire fighting should include the practical elements which should allow the trainees to acquire the ability to （）.