The ship has a diesel engine（）a supercharger. ["with","of","on","over"]
下列选项中关于税收与国债区别，说法错误的是（）。 ["税收无须偿还，而国债必须偿还","税收属于财政收入，而国债不属于财政收入","税收具有强制性，而国债是自愿的信用关系","税收对象和税率事先规定，而国债利率受诸多因素的影响"]
对进程的说法正确的是（）。 ["是一个系统软件","与程序概念等效","是存放在内存中的程序","是执行中的程序"]
（）are supplied by main switchboard directly. ["Suez Canal searchlight, air compressor and air conditioning compressor","Air compressor, boiler blower and refrigeration plant","Boiler blower, Suez Canal searchlight and refrigeration plant","Suez canal searchlight, air compressor and boiler blower"]
The pivot pin at the base of a sheath-screw boom davit must be（）. ["inserted each time before the booms are cranked out","periodically removed for inspection and lubricated","replaced at each inspection for certification","in the locked position after the boat is cradled and griped dow"]
什么叫发电设备平均利用率？
