GMDSS要求船舶必须配备(). ["A、DSC和SES","B、SART、TWO-WAY VHF和EPIRB","C、SART、EPIRB和518NAVTEX","D、SART、TWO-WAY VHF、EPIRB和518NAVTEX,VHF DSC"]
绘图题:如图所示为负控终端被控开关接线图,(K为负控终端跳闸出口继电器触点),请评价图(a)和图(b)的优缺点?
已知A、B两点的X、Y坐标分别为A(486.80,1872.31),B(630.58,1633.75),则两点之间水平距离为()。 ["283.794","290.610","265.812","278.533"]
无限航区远洋船舶上配备的EPIRB为(). ["A、VHFEPIRB和406MhzEPIRB","B、1.6GhzEPIRB一个","C、1.6GhzEPIRB或406MhzEPIRB任选一个","D、406MhzEPIRB一个"]
进行氟里昂系统的气密性试验,试验介质宜采用()。 ["氮气","氧气","压缩空气","氟里昂气体"]
试述蒸发系统停车步骤?