這是一篇看圖作文，作文體裁夾敘夾議，先描寫圖畫內容，人們濫伐森林，造成水土流失，導致沙丘、沙塵暴的產生，人們重新植樹，有效抵制沙丘的進攻；再議論圖畫所暗示的深刻含義，呼吁人們重視生態平衡。

　　參考例文：

　　As is shown in the pictures，trees play an important part in water and soil conservation. In the left picture， people are fleeing from sand dunes because they cut down all trees. In the right picture， people have planted many trees and the sand has retreated.

　　People should realize the important relation between human and nature. If we continue to destroy forests， destroy the balance of nature， the real victims will be us humans.

　　It's never too late to mend. After suffering from sand storms， people have now realized the importance of trees in water and soil conservation. They are planting more and more trees to fight against the greedy desert.