潜动指只加入电流或只加入电压信号的情况下，继电器就能动作。（  ）

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69481' and id < 4500291 and id<>'4500291' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69481' and id > 4500291 and id<>'4500291' order by id asc limit 5