真空断路器主要用于（    ）电压等级。

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69490' and id < 4501376 and id<>'4501376' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69490' and id > 4501376 and id<>'4501376' order by id asc limit 5