Leg press, deadlifts, RDLs, lunges, leg extensions, leg curls, hack squats, split squats. All those will hit your legs, plus there variations. Do some sprints, run hills, stairs, those will hit your legs. Im sure there are more lifts I can't think of this second as well.
While natural gas occurs in nature as a mixture of methane and other gases, propane is actually a byproduct of both petroleum refining and natural gas processing.
Natural gas is the gas petroleum product that is pulled from the earth. Oil is a refined product from crude which is used for lubricants. Gasoline is a further refined petroleum liquid which is used for fuels. Gas can be a refined product of natural gas that separates the butanes, propanes, methanes, and etc. Remember, refining is the process of turning crude and natural gas into something we can use.