natural crook timber

例句：

1. 1. The buildersused crooked timber to build thehouse.
   建筑工人使用弯曲的木材建造了房子。
2. 2. The old tree had been felled with a crooked timber axe.
   那棵老树被一把弯曲的斧头砍倒了。
3. 3. Thecrooked timber wasdifficult to work with and causedmany problems.
   弯曲的木材难以加工，导致了许多问题。