钢结构涂装用防火涂料按涂层厚度共分为（ ）类。

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SQL Error: select id,body,options from ***_enewstiku where sourceid='24588' and id < 2110331 and id<>'2110331' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='24588' and id > 2110331 and id<>'2110331' order by id asc limit 5