depositional system of coal-bearing series

例句：

1. 1.The depositional system of the coal-bearing series is crucial for understanding the geological history of the region.
   含煤地层沉积系统对于理解该地区的地质历史至关重要。
2. 2. The study of the depositional system helps us better understand the formation of rocks and sediments.
   研究沉积系统有助于我们更好地理解岩石和沉积物的形成。
3. 3. The depositional system of the coal-bearing series plays a significant role in the development of the region's economy.
   含煤地层的沉积系统在该地区经济发展中起着重要作用。