会变绿的树 / The tree turns green

Cats like to scratch the chairs or sofas by nature,cats’ masters were bored by it.Combine an ordinary chair with a scratching post.Embed the green and yellow corrugated papers which cats love to scratch in the back of the chair hierarchically,take the shape of trees.When cats scratch out the yellow corrugated paper,the green corrugated paper will be showed.After the yellow corrugates paper has been scratched out completely,a green tree will be appeared,meanwhile,the chair will be endued with endless vitality.