In addition to being the first to transmit voice over radio, Reginald Fessenden developed amplitude modulation, or as we call it today, AM.是什么意思_In addition to being the first to transmit voice over radio, Reginald Fessenden developed amplitude modulation, or as we call it today, AM.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句