电力变压器带载试车时间应不小于()h。
A.12
B.24
C.36
D.48
E72
参考答案:B
New surveys suggest that people are more stressed and working longer hours than ever with
technological tools constantly ______. [ ]
A. updating
B. updates
C. updated
D. to update
钢轨探伤车探伤系统小车控制盘上,报警指示灯亮说明()。
A、气压不足
B、油压不足
C、电源不足
D、小车架有危险