big

black

brown

bucket

capacity

car

carbon

coal

digger

digging

dust

earth

ecology

energy

enormous

environment

environmental

excavation

excavator

exploitation

firm

fossil

fuel

giant

ground

heavy

industrial

industry

machine

metal

method

mine

nature

open

openway

ore

pile

pit

pollution

power

resource

route

steel

strip

technology

train

utility

vehicle

wheel

work