resin

例句：

1. 1. The ancient tree has a thick layer of resin on its bark.
   这棵古老的树的树皮上覆盖着厚厚的一层树脂。
2. 2. Resin is used to make varnishes and polishes.
   树脂被用来制作油漆和抛光剂。
3. 3. The ancient tree has a thick layer of resin on its bark.
   这棵古老的树的树皮上覆盖着厚厚的一层树脂。