—个树形文件系统体现了（ ）模式。

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SQL Error: select id,body,options from ***_enewstiku where sourceid='30258' and id < 2447794 and id<>'2447794' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='30258' and id > 2447794 and id<>'2447794' order by id asc limit 5