英文關鍵字
big
brown
cast
coal
desert
digger
digging
dry
energy
environmental
equipment
excavator
fuel
generation
germany
giant
ground
heavy
industrial
industry
large
machine
metal
mine
mines
mining
open
opencast
overburden
pit
pollution
power
sand
sky
spreader
strip
surface
technology
tool
vehicle
welzow
wheel
work