同步电动机所输入的交流电频率与转速之比为恒定值。    

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68475' and id < 4421200 and id<>'4421200' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68475' and id > 4421200 and id<>'4421200' order by id asc limit 5