英文關鍵字
activity
belt
business
cobblestone
concrete
construction
conveyor
crushed
crusher
dig
earth
engineering
environment
equipment
extraction
factory
geology
gravel
ground
heap
heavy
industrial
industrialized
industry
large
loading
lorry
macadam
machine
machinery
manufacturing
material
metal
mine
mineral
pebble
production
quarry
quarrying
rocas
rock
sand
site
stack
steel
stone
technology
transportation
truck
work