单项选择题
The blocking or absence of fire dampers can cause（）.
A.the accumulation of explosive gases B.faster cooling of the fire C.the fire to spread through the ventilation system D.fixed foam systems to be ineffective
单项选择题 The bilge pump on a fishing vessel（）.
单项选择题 The best method of extinguishing a class A fire is to（）.
单项选择题 The BEST method of applying foam to a fire is to（）.
