单项选择题
Which of the listed classes of fire would most likely occur in the engine room of a vessel?（）
A.Classes A and B B.Classes B and C C.Classes C and D D.Classes A and D
单项选择题 If ignited, which of the listed materials would be a class "B" fire?（）
单项选择题 Which statement concerning the collection of fresh water is FALSE?（）
单项选择题 The class of fire on which a blanketing effect is essential to extinguish the fire is （）.
