运行20年的瓷绝缘子串在雾天突然击穿，基本可判断为(  )(每题0.5 分)（0.5）

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69426' and id < 4495688 and id<>'4495688' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69426' and id > 4495688 and id<>'4495688' order by id asc limit 5