coal quality log

例句：

1. 1. The coal quality log shows that the coal is high in ash content and low in sulfur content.
   煤质日志显示，该煤含灰量高，硫分低。
2. 2.The coal quality log was used to determine the optimal mining depth for this type of coal.
   煤质日志被用来确定这种煤的最佳开采深度。
3. 3. The coal quality log was analyzed to identify any potential environmental hazards associated with the mining process.
   对煤质日志进行分析以识别与采矿过程相关的任何潜在环境危害。