New Words：

bark [bɑ:k] n. 树皮
rough [rʌf] adj. 粗糙的；不平滑的
smooth [smu:ð] adj. 光滑的；平整的

Sample Sentences：

Those trees have very beautiful white bark.
The dog barked when the stranger came near.

The bus went up and down on the rough road.
He felt the rough bark of the tree with his hand.

Her skin is as smooth as silk.
The path through life is not always smooth or easy.

标签: none