black
block
central
clean
coal
coal burning
coals
cube
dark
deposits
dirty
ecology
effect
energy
environment
exploitation
extract
extraction
fuel
fuels
gas
hand
heat
heating
hold
hot
industry
lignite
lump
man
manufacturing
material
metallurgical
mine
miner
mineral
mines
mining
nature
power
power station
resources
shovel
show
stone
types
uses of
worker