as hard as stone

例句：

1. 1. The mountain was so steepthat it was as hard as stone toclimb.
   那座山太陡峭了，攀登起来就像石头一样困难。
2. 2. Herdetermination was as hard asstone, and she never gaveup.
   她的坚定意志坚如磐石，从未放弃。
3. 3. The old house wasas hard as stone, but the newone is much more comfortable.
   这座老房子坚固如石，但新房子舒适多了。