已知椭圆方程 ，那么它的焦距是

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='32862' and id < 2619420 and id<>'2619420' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='32862' and id > 2619420 and id<>'2619420' order by id asc limit 5