A.電場(chǎng)B.電荷C.磁場(chǎng)D.磁感應(yīng)場(chǎng)
A.阻低頻;通高頻B.阻高頻;通低頻C.電壓發(fā)生突變D.通交流
A.5700歐B.57歐C.570歐D.57000歐