单项选择题
A.cross connection line between two main fire lines
B.special wrench for tightening couplings in a fire hose line
C.tackle rigged to support a fire hose
D.None of the above
单项选择题 A small fuel spillage has occurred during helicopter refueling. After the leak has been stopped and fire-control personnel have been notified and are standing by，the next step is to（）.
单项选择题 A ship must have a self-contained breathing apparatus to be used as protection from gas leaking from a refrigeration unit. To meet this requirement，you may use（）.
单项选择题 A ship helicopter landing deck on which fueling operations are conducted must have a fire protection system that is capable of discharging at 100 psi pressure a foam spray of at least（）.