金属都是铁磁性材料。（   ）

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69320' and id < 4487842 and id<>'4487842' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69320' and id > 4487842 and id<>'4487842' order by id asc limit 5