单项选择题
The discharge side of every fire pump must be equipped with a（）.
A.gate valve B.pressure gauge C.check valve D.strainer
单项选择题 The discharge from a carbon dioxide fire extinguisher should be directed（）.
单项选择题 The disadvantage of using CO2 is that the（）.
单项选择题 The collision bulkhead shall be of（）.
