题目6单选题
Typical marine propulsion plants include____ directly coupled to the vessel's single large-diameter, fixed-pitch propellerA. a single, long-stroke, slow-speed, turbocharged, two-stroke diesel engineB. a single, long-stroke, medium-speed, turbocharged, four-stroke diesel engineC. two medium-speed, turbocharged, four-stroke diesel enginesD. a variable-speed AC generator