moorstone

例句：

1. 1. The moorstone is a fossilized rock that has been formed over millionsof years.
   石炭是一种经过数百万年形成的化石岩石。
2. 2. The moorstone wasused as fuel for heating homes during thecold winter months.
   在寒冷的冬天，石炭被用作取暖燃料。
3. 3. The moorstone was discovered in a remote areaof the country, and it'snow being studied for its potential use inenergy production.
   这个国家的一个偏远地区发现了石炭，目前正在研究其潜在的能源生产用途。