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.
The following is a brief summary highlighting the main differences of these fuels. Much more comprehensive details of the fuel properties and compositions is available from other web sources and online databases. Compressed Natural Gas or CNG is stored on the vehicle in high-pressure tanks - 20 to 25 MPa (200 to 250 bar, or 3,000 to 3,600 psi). Natural gas consists mostly of methane and is drawn from gas wells or in conjunction with crude oil production.