距离保护采用三段式，分为相间距离保护和（   ）。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69518' and id < 4503714 and id<>'4503714' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69518' and id > 4503714 and id<>'4503714' order by id asc limit 5