英文關鍵字
aerial
asbestos
bucket
cast
copter
day
development
disappear
drone
dump
ecological
ecology
environment
excavator
extract
field
flycam
geology
grader
heavy
hill
hole
industry
labor
ledge
machine
mechanism
mineral
mining
morning
open
ore
pit
production
quadrocopter
quarry
road
serpentine
steps
stone
sunny
technology
tractor
transport
transportation
view
wheel
yellow