Dsf
abbr. 色散移位光纤（Dispersion Shifted Fiber）；个人金融理财业务（direct sales force）
🗣️ 情景例句
because the doctors and nurses are so busy?
因为医生和护士们都非常忙？
I enclosed some photographs in my letter.
我在信封里装了一些相片。
He's fine, thanks.How's Emma?
他很好，谢谢。埃玛好吗？