正弦电路的功率因数，下列叙述的正确的是(     )。

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69437' and id < 4496813 and id<>'4496813' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69437' and id > 4496813 and id<>'4496813' order by id asc limit 5