The source of this nitrogen is exhaust from cars, trucks, lawn mowers and coal-fired electric utility plants (including waste-to-energy facilities).
(The source of this nitrogen; is; exhaust from cars, trucks, lawn mowers and coal-fired electric utility plants (including waste-to-energy facilities) (exhaust; is The source of; this nitrogen)
The source of this nitrogen exhaust
is is The source of
exhaust from cars, trucks, lawn mowers and coal-fired electric utility plants (including waste-to-energy facilities
this nitrogen