单项选择题
A.male coupling at both ends B.female coupling at both ends C.female coupling at the nozzle end and a male coupling at the hydrant end D.male coupling at the nozzle end and a female coupling at the hydrant end
A.blows the fire back toward the vessel B.comes over the bow C.comes over the stern D.comes over either beam
A.alternate expansion and contraction as water in a liquid state becomes a vapor B.absorption of smoke and gases as water is converted from a liquid to a vapor C.rapid contraction as water is converted from a liquid to a vapor D.rapid expansion as water absorbs heat and changes to steam