英文關鍵字
activity
belt
business
cobblestone
concrete
construction
conveyor
crisis
crushed
dig
earth
engineering
excavator
extraction
factory
gallop
gravel
ground
heap
heavy
industrial
industry
iron
large
lorry
macadam
machine
machinery
manufacturing
material
metal
mine
miner
mineral
mountain
outside
pebble
production
quarry
rocas
rock
sandpit
stack
stone
technology
transportation
truck
wool
work
works