短語(yǔ)詞組短語(yǔ)frequency following spectrum 頻率跟隨譜ultralow frequency dielectric spectrum 超低頻介電譜low frequency line spectrum 低頻線譜switching frequency spread spectrum 切換頻率展頻frequency modulation spectrum 頻率調(diào)制譜frequency -spectrum therapeutic 頻譜治療儀frequency hop spectrum communication 跳頻擴(kuò)譜frequency response spectrum 頻率及應(yīng)譜frequency relaxation spectrum 頻率松弛譜 返回 frequency spectrum