在检验电能表时被检表的采样脉冲应选择确当，不能太少，至少应使两次出现误差的时间间隔不小于10s。
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在三相负载平衡的情况下，某三相三线有功电能表C相电流未加，此时负荷功率因数为0.5时，电能表停转。
A. 正确
B. 错误
在三相负载平衡的情况下，三相三线有功电能表A相电压未加，此时负荷功率因数为0.5时电能表计量正确。
A. 正确
B. 错误
You notice that the performance of the database has degraded because of frequent checkpoints. Which two actions resolve the issue（）
A. Disable automatic checkpoint tuning.
B. Check the size of the redo log file size and increase the size if it is small.
C. Set the FAST_START_MTTR_TARGET parameter as per the advice given by the MTTR Advisor.
Decrease the number of redo log members if there are more than one redo log members available in each redo log group.
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