英文關鍵字
blue
bright
build
bulldozer
chimney
construction
dark
dig
dirt
equipment
evening
excavation
excavator
ground
heavy
horizon
hydraulic
industrial
industry
machine
machinery
modern
operate
outdoor
plant
pollution
pour
power
refinery
shadow
silhouette
site
sky
skyline
soil
sunlight
sunset
system
technology
tractor
turn
vehicle