Usfs
[医]United States Frequency Standard
🗣️ 情景例句
How many stamps do I need?
我需要多少邮票？
If you wouldn't mind, I could use a hand.
如果你不介意的话，我可能要你帮个忙。
At that moment Lucy came into the library.
正在那时候，露茜走进图书馆。