Kömür ve doğal gaz doğal yakıtlardır.
- Coal and natural gas are natural fuels.
Hidroelektrik yenilenebilir bir kaynaktır ama petrol, kömür ve doğal gaz değil.
- Hydropower is a renewable resource, but oil, coal and natural gas are not.
Natural-gas prices.
... And oil and natural gas production are higher than they've been in years. But I also believe ...
... Number three, we've got to control our own energy. Now, not only oil and natural gas, ...