Sffd
abbr. step-function frequency discriminator 阶跃函数鉴频器
🗣️ 情景例句
Before the barbeque let's sharpen all the knives.
烧烤之前先把刀磨一磨。
He recommended me for the post of principal.
他推荐我担任校长。
The modern weather models work with a grid of points of the order of sixty miles apart,
现代气象模型以一个坐标图来显示，图中每个点大约是间隔60英里。