已知{an}为等差数列，a1+a5+a9=105，则S9=（  ）

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24156' and id < 2090007 and id<>'2090007' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24156' and id > 2090007 and id<>'2090007' order by id asc limit 5