tree scale

例句：

1. 1. The tree scales are a naturalpart of the forest ecosystem.
   树皮是森林生态系统的自然组成部分。
2. 2. The bark of theoak tree is thick and rough.
   橡树的树皮厚且粗糙。
3. 3. Thetree scales were used to make furniturein ancient times.
   古代用树皮制作家具。