機器
big
black
breed
burning
carbon
coal
control
deliver
dig
dirty
energy
environment
extraction
flat
fuel
gold
gravel
hard
heap
heat
icon
industrial
industry
large
messy
mine
mineral
mountain
natural
object
ore
pieces
power
railway
resource
rock
rough
shadow
sign
site
solid
stack
stock
stone
strong
texture
transportation
work