切除空载线路时产生过电压的根本原因是(    )。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69522' and id < 4504120 and id<>'4504120' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69522' and id > 4504120 and id<>'4504120' order by id asc limit 5