已知一节点向负荷供电，无功功率为Q，视在功率为S，则功率因数角φ为(    )

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68479' and id < 4421477 and id<>'4421477' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='68479' and id > 4421477 and id<>'4421477' order by id asc limit 5