采用电流，电压表测量接地电阻时，一般电压辅助接地棒P与接地体引出线E的距离为(  ）。

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69491' and id < 4501626 and id<>'4501626' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69491' and id > 4501626 and id<>'4501626' order by id asc limit 5