单项选择题
A.any wire rope used for mooring
B.a fire-warp
C.a mooring line running diagonally to the keel
D.a mooring line perpendicular to the keel
单项选择题 A spanner is a（）.
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（）.