Methane can be formed by the decay of natural materials and is common in landfills, marshes, septic systems and sewers.
(Methane; can be formed; by the decay of natural materials) (Methane; is; common in landfills, marshes, septic systems and sewers)
Methane Methane
can be formed is
by the decay of natural materials
common in landfills, marshes, septic systems and sewers