Kömür ve doğal gaz doğal yakıtlardır.
- Coal and natural gas are natural fuels.
Kömür, doğal gaz ve petrol, milyonlarca yıl önce yaşamış bitki ve hayvanların kalıntılarıdır.
- Coal, natural gas and oil are the remains of plants and animals that lived millions of years ago.
Natural-gas prices.
... the American people believe that. I will fight for oil, coal and natural gas. And the proof, ...
... one of the reasons why is natural gas extracted safely ...