无烟煤是一种最有价值的煤，它燃烧慢，烟很少但火焰却很大。

The anthracite is the most valuable type of coal. It burns slowly, with little smoke and a very hot flame.

youdao

无烟煤是一种最有价值的煤，它燃烧慢，烟很少但火焰却很大。

The anthracite is the most valuable type of coal. It burns slowly, with little smoke and a very hot flame.

youdao