英文關鍵字
aerial
black
coal
earth
electricity
energy
engine
environment
equipment
fossil
fuel
geology
industry
locomotive
machine
mining
nature
power
railroad
railway
rock
train
transit
transport
transportation
英文關鍵字
aerial
black
coal
earth
electricity
energy
engine
environment
equipment
fossil
fuel
geology
industry
locomotive
machine
mining
nature
power
railroad
railway
rock
train
transit
transport
transportation