the grassland degradation的用法和样例：
例句
- Grassland degradation of Tongde County was caused by both natural factors and human factors.
同德县的草地退化是自然因素和人为因素共同综合作用的结果。 - Due to the unreasonable utilization, the eco-system of the grasslands has been damaged seriously and the deterioration area is keeping expanding.
由于不合理的利用，草原生态系统遭到了严重破坏，草地退化面积不断扩大。
