Sffd
abbr. step-function frequency discriminator 阶跃函数鉴频器
🗣️ 情景例句
I'll call the Staten Island Ferry lost-and-found office.
我来打电话给Staten岛渡轮的失物招领处。
How much do you charge for sending a cable transfer to London?
发一张到伦敦的电汇，要收费多少？
Are you crazy?
你疯了吗？