单项选择题
The survival craft is manufactured with fire retardant（）.
A.foam B.marine plywood C.steel D.fiberglass
单项选择题 The signal for fire alarm on a ship must be indicated（）.
单项选择题 The patrolman，while on duty on a passenger vessel，must have in his possession a(n)（）.
单项选择题 The only type of helicopter that may be refueled with the engine running and the blades turning is（）.
