Fuel used for heating (3)
I believe the answer is:
gas
(Other definitions for gas that I've seen before include "natural resource" , "Petrol (US)" , "Neon, for example" , "Hydrogen, for example" , "Eg, hydrogen" .)
I believe the answer is:
gas
(Other definitions for gas that I've seen before include "natural resource" , "Petrol (US)" , "Neon, for example" , "Hydrogen, for example" , "Eg, hydrogen" .)