以下（   ）调速方式属于变转差率调速。

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69328' and id < 4488237 and id<>'4488237' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69328' and id > 4488237 and id<>'4488237' order by id asc limit 5