Cylinder lubrication oil for low speed main propulsion diesel engines is admitted to each
A. the power stroke
B. the compression stroke
C. low load operation only
D. periods of standby
当接通气象雷达“STB”功能时，可控制天线从零基准位置向上，向下各___之间的俯仰运动：
A. 15°
B. 20°
C. 30°
D. 45°
The cooling of the piston is carried out by circulating _____ across the underside of the
A. sea water
B. scavenging air
C. lubricating oil
D. fuel oil
公犬前列腺肥大的临诊特征症状是
A. 排便困难
B. 排尿困难
C. 血尿
D. 尿频
E. 少尿
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