hard as nails

• 铁石心肠

hard as nails的用法和样例：

例句

1. They are merciless, with hearts as hard as nails.
   他们冷酷无情，铁石心肠。
2. Mrs. Macbeth has a heart as hard as flint.
   麦克白夫人生来一副铁石心肠。
3. They are merciless, with hearts as hard as nails.
   他们冷酷无情，铁石心肠。
4. He is as hard as flint where business is concerned.
   他在生意上是冷酷无情的。

词汇搭配

• as hard as nails 身体结实