UPS的电源告警线使用串口线与MU连接，并设置好哪三路告警参数？（）
A.UPS故障
B.市电停电
C.低压告警
D.湿度告警
参考答案：A, B, C
试在图中标出A、B、C三处磁感线方向．
It was not so much the many blows he receivedthe lack of fighting spirit that led to his losing the job. ( )
A．for
B．of
C．as
D．like
