CRH1的每个客室空调有()压缩机。 ["1个","2个","3个","4个"]
10kV电缆终端头制作前,要对电缆用2500V兆欧表测量其绝缘电阻,要求绝缘电阻不小于()。 ["50MΩ;","100MΩ;","150MΩ;","200MΩ。"]
引气剂起什么作用?
飞行前航行情报服务通常采用:(). ["机组自我准备方式进行","提供讲解服务方式进行","校核单方式进行","设立航行通告栏方式进行"]
CRH1每车有()室内温度传感器。 ["2个","4个","6个","8个"]
发泡剂泡多大合适?