unfixed soil

例句：

1. 1. The unfixed soil in the area is prone to erosion.
   该地区的未固定土壤容易侵蚀。
2. 2. The construction of roads and bridges requires careful management of unfixed soil.
   修建道路和桥梁需要仔细管理未固定的土壤。
3. 3. The farmers have been working on improving the quality of unfixed soil for years.
   农民们多年来一直在努力提高未固定土壤的质量。