单项选择题
The supercharger takes air out of the surrounding atmosphere and then feeds it to the engine’s （）.
A.inlet valves B.exhaust valves C.emergency valves D.run-return valves
单项选择题 The successful operation of any engine or machine and （） depend on effective lubrication.
单项选择题 The starting of a marine diesel engine is generally carried out with the assistance of （）.
单项选择题 The starting air system usually has （） to prevent starting if anything is not in order.
