A'ai coal mining area的用法和样例：
- The coal mining area is in the center of the basin.
- Wulunshan Coal Mining Area in Guizhou has intact geological structure and high CBM content.
- The present research situation of water-inrush from coal mining area floor was briefly introduced.
- The stability of composite slope, within first mining area in the 3rd Baiyinhua opencast coal mine, was analyzed.