noncaking coal

例句：

1. 1. The noncaking coal is used as a fuel in power plants.
   无烟煤被用作发电厂的燃料。
2. 2.The bituminous coal is mined from deep within the earth's crust.
   烟煤是从地壳深处开采出来的。
3. 3. Coal mining has been a major industry in many countries for centuries.
   煤炭开采是许多国家几个世纪以来的主要产业。