设{an}为等差数列，公差d=﹣2，sn为其前n项和，若s10=s11，则a1=

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24233' and id < 2095855 and id<>'2095855' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24233' and id > 2095855 and id<>'2095855' order by id asc limit 5