bur-bark

例句：

1. 1. The tree's bur-bark is thick and tough.
   这棵树的树皮又厚又硬。
2. 2.The old oak tree has a rich bur-bark that is used for making furniture.
   那棵老橡树有着丰富的树皮，用来制作家具。
3. 3.The bur-bark of the tree is a natural insulator, keeping the tree cool in hot weather.
   树皮是树木的一种天然绝缘材料，在炎热的天气中保持树木凉爽。