500kV系统的平均额定电压为(    )

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68479' and id < 4421476 and id<>'4421476' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68479' and id > 4421476 and id<>'4421476' order by id asc limit 5