单项选择题
A gypsy or gypsyhead is a（）.
A.punt used for painting over the side B.small, reciprocating steam engine C.spool-shaped drum fitted on a winch D.swinging derrick
单项选择题 A hydrostatic release mechanism for a liferaft（）.
单项选择题 A hygrometer is a device used for determining（）.
单项选择题 A large oil fire on the deck of a ship can be fought most effectively with（）.
