Considering its rich resources and utilization range, people find lean coal has excellent economic benefit.

同时根据贫煤的资源量和使用范围，使用贫煤具有良好的经济效益。

youdao

Considering its rich resources and utilization range, people find lean coal has excellent economic benefit.

同时根据贫煤的资源量和使用范围，使用贫煤具有良好的经济效益。

youdao