Sfn
abbr. Sound Field Nonunifornity （声场不均匀度）
🗣️ 情景例句
What's wrong, Susan?
怎么啦， Susan？
I'm afraid you will miss your plane.
我怕你会错过飞机。
I had a letter from my sister yesterday.
昨天我收到了姐姐的一封信，