a tough nut的用法和樣例：
例句
- I asked her for the money, but she was a tough nut to crack and I went away without it.
我向她要錢，但她這個人很難對付，因此我空手而歸。 - The final exam was a tough nut.
畢業考試不好對付。 - She's a tough nut to crack; I don't think she'll give us permission.
她這個人不好說話，我想她不會答應我們的。
辭彙搭配
- a tough nut to crack 難對付的人
