英文關鍵字
additives
background
black
burn
burning
carbon
cast
coal
combustion
commodities
commodity
construction
conveyor
dirty
dust
earth
energy
environmental
equipment
excavator
falls
fire
fossil
fuel
furnace
geology
global
heavy
hot
industrial
industrialization
industry
iron
machinery
materials
melting
mine
mining
natural
ore
pile
plant
processing
raw
red
stream
transportation
warming
work