整流器的一只快速熔断器熔断发出（），二只快速熔断器熔断发出跳闸信号。
参考答案：报警信号
— Did you look up the time of trains to Shanghai?
— Yes, the earliest train is ___ to leave at 5:30 am. [ ]
A. likely
B. about
C. possible
D. due
支撑座两外侧面磨耗深度大于（）时堆焊后磨平。
A.2mm
B.3mm
C.4mm
D.5mm
