单项选择题
The preferred type of pollution control for oil spills on the water is(are) （）.
A.straw B.booms C.skimmers D.chemical dispersants
单项选择题 The preferred agent used in fighting a helicopter crash fire is（）.
单项选择题 The outlet at a fire hydrant may be positioned anywhere from horizontal to pointing（）.
单项选择题 The muster list shows each rig hand’s muster station，his duties during abandonment，basic instructions，and（）.
