Like the millipedes, centipedes are highly segmented (15 to 177 segments), but with only one pair of walking legs per segment (millipedes have two legs per segment). The head of a centipede has a pair of antennae, jaw-like mandibles (called forcipules) and other mouthparts.
Although compressed natural gas (CNG) is a fossil fuel like diesel, gas and coal, it is far different in terms of its impact on the natural environment.
Propane is a hydrocarbon (C 3 H 8) and is sometimes referred to as liquefied petroleum gas, LP-Gas or LPG. Propane is produced from both natural gas processing and crude oil refining. It is nontoxic, colorless and virtually odorless. As with natural gas, an identifying odor is added so the gas can be readily detected.