某二叉树的中序序列为BDCA,后序序列为DCBA，则前序序列为（ ）。

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SQL Error: select id,body,options from ***_enewstiku where sourceid='28853' and id < 2351156 and id<>'2351156' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='28853' and id > 2351156 and id<>'2351156' order by id asc limit 5