classification of soil and rock

例句：

1. 1. The scientists classified the new species into different groups.
   科学家们将新物种分成不同的组。
2. 2. The museum has a classification chart for visitors to follow.
   博物馆有一个分类图表供游客参考。
3. 3. The researchers have made significant progress in their classification of plant DNA.
   研究人员在植物DNA的分类方面取得了重大进展。