根据电力系统频率特性和电压特性，可以得知(    )

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69460' and id < 4498508 and id<>'4498508' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69460' and id > 4498508 and id<>'4498508' order by id asc limit 5