英文關鍵字
bulldozer
closeup
coal
combine
construction
crane
development
energy
engineer
engineering
enrichment
enterprise
excavator
factory
frost
geodesy
giant
industry
iron
labor
machine
machinery
mechanism
mine
miner
motion
mountains
movement
outdoors
production
profession
quarry
rocks
rope
rubber
site
snow
sorting
special
stones
tipper
tractor
transport
volume
wheels
winter