英文關鍵字
blue
business
cargo
chimney
city
cloud
clouds
container
daugava
day
ecology
electricity
energy
environment
factory
fog
forest
fuel
global
industrial
industry
lake
landscape
latvia
morning
nature
oil
pollution
power
river
sky
smog
smoke
smokestack
station
steam
sunny
sunrise
sunset
technology
terminal
transport
transportation
trees
water
white
winter