【电学】用一定的频率振动锤击【电学】频率差拍

audio-frequency push-pull ampli-fier

relative frequency

３０赫－２０千赫\nacoustic frequency【声】;audible frequency【声】;audio frequency【声】

Arrhenius frequency factor

acoustical telegraphy【通信】;audio frequency telegraph【通信】;

vibrating-reed frequency sensor

frequency function

fundamental frequency