英文關鍵字
activity
belt
bulldozer
business
cobblestone
concrete
construction
conveyor
crisis
crushed
dig
dump
earth
engineering
equipment
extraction
factory
gallop
gravel
heap
heavy
hole
industrial
industry
iron
large
lorry
macadam
machine
machinery
manufacturing
material
metal
mine
mineral
mountain
opencast
outside
pebble
pouring
quarry
rocas
rock
sand
sandpit
stack
stone
technology
truck
working