电弧之所以能维持燃烧，是因为有足够强的（  ）存在。  

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69482' and id < 4500348 and id<>'4500348' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69482' and id > 4500348 and id<>'4500348' order by id asc limit 5