英文關鍵字
nobody
fuel
pump
industry
oil
steel
power
color
outdoors
scenics
fossil
lever
rig
pipeline
equipment
energy
prairie
gas
resource
pulley
concepts
geology
natural
tank
pollution
machine
counterweight
wealth
prosperity
oilwell
gasoline
industrial
backgrounds
reservoir
exploration
sky
sunlight
silhouette
sunset
orange
red
dark
twilight
row
many