a=1∠120°为旋转因子，1+a+a^2 等于多少(  )。

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69458' and id < 4498242 and id<>'4498242' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69458' and id > 4498242 and id<>'4498242' order by id asc limit 5