sterane to hopane ratio

例句：

1. 1. The study found that the sterane to hopane ratio in the soil was significantly higher than that in the nearby forest.
   研究发现，土壤中的甾烷/藿烷比显著高于附近的森林。
2. 2.The ratio of sterane to hopane in the rocks is a key indicator of their geological age.
   岩石中甾烷与藿烷的比率是判断其地质年代的关键指标。
3. 3. The ratio of sterane to hopane in the sedimentary rock indicates the source of the organic matter.
   沉积岩中甾烷与藿烷的比率表明了有机物质的来源。