【单选题】Some medium and high-speed diesel engines require reduction gear units to provide a useful propeller speedIn most reduction gears, the bull gear ____.
A.
must churn the oil in the sump
B.
is connected to the propeller shaft
C.
is driven at the highest RPM
D.
compensates for alignment variations between the engine and pinion gear
【判断题】自由面上压强的任何变化,都会等值地传递到液体中的任一点
【简答题】在单反相机中,控制曝光的机构是快门和()
【简答题】在单反相机中,控制曝光的机构是( )和光圈
【单选题】中频电作用后产生镇痛作用的有效时间为是:
【判断题】交换局域网的主要特性之一是它的低交换传输延迟。局域网交换机的传输延迟时间仅高于网桥,而低于路由器。