无备用电源接线的主要优点、缺点是(    )

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68479' and id < 4421478 and id<>'4421478' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68479' and id > 4421478 and id<>'4421478' order by id asc limit 5