(来学网)干扰电最常用的电流频率组合为
  • A.
    (来学网)2000Hz与2100Hz
  • B.
    (来学网)3000Hz与3100Hz
  • C.
    (来学网)4000Hz与4100Hz
  • D.
    (来学网)5000Hz与5100Hz
  • E.
    (来学网)5500Hz与5600Hz