单项选择题
The class of fire on which a blanketing effect is essential to extinguish the fire is （）.
A.class A B.class B C.class C D.class D
单项选择题 Which of the listed classes of fire is considered as one involving electrical equipment?（）
单项选择题 Besides heat, fuel, and oxygen, which of the following is necessary for a fire to exist?（）
单项选择题 A fire and boat drill on a tank vessel shall, by regulation, include （）.
