测电容器、电力电缆、大容量变压器及电机等电容较大的设备时，兆欧表必须在额定转速状态下将测电笔接触或离开被测设备，以避免因电容放电而损坏摇表。
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提速道岔控制电路中有5个继电器。
A. 正确
B. 错误
Which two statements are true about alerts（）
A. Clearing an alert sends the alert to the alert history.
B. Response actions cannot be specified with server-generated alerts.
C. The nonthreshold alerts appear in the DBA_OUTSTANDING_ALERTS view.
D. Server-generated alerts notify the problems that cannot be resolved automatically and requireadministrators to be notified.
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