- I am afraid it has dregs under the coal.
- We need to replenish our stocks of coal.
- She piled on more coal before the fire go out.
- I add the coal on the flame continuously.
- They are ventilating the sap of a coal mine.
- Prohibition was laid on the export of coal.
coal oil coal coal geology and exploration coal bed methane development coal worker s pneumoconiosis Coal serial hydrocarbon rock coal mine accidents database coalbed methane accumulation coal quality characteristics Coal Mining Industry Company coal winning machine cabinet coalbed methane seepage flow