断路器拒绝分闸应当如何处理？
After stopping oily water separator, sea water should be permitted for （） minutes,（）should be closed after stopping pump to reduce oxidation corrosion of inner wall. ["15；inlet value","15；inlet and outlet value","30；inlet value","30；inlet and outlet value"]
找出主要影响质量的质量控制工具是（） ["因果分析图","排列图","直方图","控制图"]
Ship’s steering gear refers to（）. ["cargo handling machines","deck winches and derricks","engine-room tools","course controlling system"]
一台三相异步电动机的频率为50Hz，磁极数为10，当接通三相交流电源后所产生的旋转磁场的转速为（） ["600r\/min","1500r\/min","750r\/min","500r\/mi"]
断路器液压回路“机构故障”（超时打压）应当如何处理？
