低压线路分支杆的杆型有() ["Y字形","丁字形","十字形","V字形"]
脂砚斋评语
当循环氢压缩机出现故障停运时,()。 ["A、降低原料油量","B、0.7MPa/min紧急泄压系统自启动","C、2.1MPa/min紧急泄压系统自启动","D、打开2.1MPa/min副线"]
电缆故障原则上可分()几种类型。 ["接地故障","短路故障","断线故障","闪络性故障","临时性故障"]
任何单位和个人发现船舶及其有关作业活动造成或者可能造成海洋环境污染的,应当立即就近向谁报告?
红学