[本科]允许式高频保护必须使用双频制，而不能使用单频制。（  ）

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69487' and id < 4500970 and id<>'4500970' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69487' and id > 4500970 and id<>'4500970' order by id asc limit 5