使用蒸汽时,应先打开蒸汽管线末端的(),以便把冷凝水排净。 ["阀门","消压阀","放空阀","疏水器"]
使用GSM辅助系统完成一个BSC的局数据时,唯一确定每个小区所对应的TRX号的文件是(). ["A、网络规划报告","B、BSC设计报告","C、勘测报告","D、小区分配草表"]
“YAG”中文名称是:(). ["人造钇铝榴石","人造钆镓榴石","人造钛酸锶"]
区分水热法合成红宝石与红宝石时,要观测:(). ["折射率","有无同生气液包体","有无金红石或锆石等同生包裹体"]
容器的高、低液位报警参数是()的。 ["液位报警仪预测到","计算机监测到","液位仪表监测到","事先人为设定"]
铜热电阻的电阻值与温度之间的函数关系是什么?