原级：coalfield
1. In the coalfields of eastern Kentucky, it's known as the hoot owl shift.
2. Construction of an integrated coal project at two coalfields in Inner Mongolia autonomous region has begun.
3. There are six large coalfields in the region, each with 10 billion tons of proven reserves.
4. " The nation today has several coalfields that have reserves of 10 billion tons, " he said.
5. coalfields
5. There are five coalfields with reserves of over 10 billion tons each.