百度
谷歌
图片
维基
百科
signal frequency spectrum
signal function
signal gantry
signal generating device
signal generator
signal glass
signal glassware
signal grid
signal ground
signal group
signal gun
signal hair
signal halyard
signal handle
signal handling equipment
signal headway
signal horn
signal hose
signal hypothesis
signal identification
signal imitation
signal impulse
signal indication
signal indication checking
signal indication lamp
signal indicator
signal information
signal injector
signal input
signal input interrupt
signal function
signal gantry
signal generating device
signal generator
signal glass
signal glassware
signal grid
signal ground
signal group
signal gun
signal hair
signal halyard
signal handle
signal handling equipment
signal headway
signal horn
signal hose
signal hypothesis
signal identification
signal imitation
signal impulse
signal indication
signal indication checking
signal indication lamp
signal indicator
signal information
signal injector
signal input
signal input interrupt
signal frequency spectrum
信号频(率频)谱