Sffd
abbr. step-function frequency discriminator 阶跃函数鉴频器
🗣️ 情景例句
It would be a great business if you could do that.
假如你能办到那样的话， 可是一笔大生意。
I'll check into it and get back to you.
我查对一下然后送还给你。
That one is only 90 fen. That's cheap.
那支笔只有九毛钱，很便宜。