载送、传递低频信号的较高频率的电流称为（ ）。

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SQL Error: select id,body,options from ***_enewstiku where sourceid='25685' and id < 2159032 and id<>'2159032' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='25685' and id > 2159032 and id<>'2159032' order by id asc limit 5