Sffd
abbr. step-function frequency discriminator 阶跃函数鉴频器
🗣️ 情景例句
Have some iced tea.
喝点冰茶吧。
No answer.
没有人接电话。
I want to pick some bananas, said Kate. I'm hungry!
“我要摘些香蕉，”凯特说，“我饿了！”