单项选择题
For most ship engines，the fuel is（）.
A.natural gas B.diesel oil C.propane D.bunker fuel
单项选择题 Diesel engines obtain combustion air through turbo chargers，blowers，or（）.
单项选择题 Diesel engines are considered safer than gasoline engines because（）.
单项选择题 Before starting any diesel or gasoline engine，which of the following must be checked? （）
