a tough nut

• n. <口>难对付的人； 与之打交道有危险的人

a tough nut的用法和样例：

例句

1. I asked her for the money, but she was a tough nut to crack and I went away without it.
   我向她要钱，但她这个人很难对付，因此我空手而归。
2. The final exam was a tough nut.
   毕业考试不好对付。
3. She's a tough nut to crack; I don't think she'll give us permission.
   她这个人不好说话，我想她不会答应我们的。

词汇搭配

• a tough nut to crack 难对付的人