滚动摩擦系数
接触器的文字符号是（）。 ["KM","KS","KT","KA"]
智力外流
由母线电容或变压器绕组电容与电磁式电压互感器引起谐振过电压的系统是（）。 ["中性点绝缘系统","中性点经消弧线圈接地系统","中性点直接接地系统（在不失地情况下）"]
In which phase is the staff training development for Cisco Unified Communications planned（） ["Design","Implement","Plan","Prepare"]
长期投资评估有哪些特点？
