接上题，x的方差（ ）。[2009年11月二级真题]

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SQL Error: select id,body,options from ***_enewstiku where sourceid='25280' and id < 2138911 and id<>'2138911' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='25280' and id > 2138911 and id<>'2138911' order by id asc limit 5