等差数列{an}中，记Sn=a1+a2+…+an，若S9=72，则a2+a4+a9=（  ）

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24155' and id < 2089792 and id<>'2089792' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='24155' and id > 2089792 and id<>'2089792' order by id asc limit 5