Sffd
abbr. step-function frequency discriminator 阶跃函数鉴频器
🗣️ 情景例句
Hi, I'm Mary.
嗨，你好，我叫玛丽。
Steele took charge of all arrangements.
斯蒂尔负责一切准备工作。
He wanted to buy a $300 watch for his wife,
他走进一家高级商店，要为妻子买一块价值300英镑的手表。