air
bank
blue
chemistry
cloudless
cold
contamination
dense
ecology
electricity
energetics
factory
fog
frosty
frozen
fuel
heat
hydroelectric
industry
landscape
line
manufacturing
misty
morning
ozone
pipe
plant
pollution
power
refinery
reflection
river
russia
sky
smoke
snow
steam
sunlight
sunrise
thermal
trees
trumpet
water
wind
winter
zai