( ( ( Ninety percent ) ( of ( controlled waste ) ) ) ( ( was ( ( ( buried ( in ( landfill sites ) ) ) and ) ( produced ( ( ( 2 million ) tons ) ( of ( methane gas ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (CD Ninety) (NN percent)) (PP (IN of) (NP (JJ controlled) (NN waste)))) (VP (VBD was) (VP (VP (VBN buried) (PP (IN in) (NP (NN landfill) (NNS sites)))) (CC and) (VP (VBN produced) (NP (NP (QP (CD 2) (CD million)) (NNS tons)) (PP (IN of) (NP (NN methane) (NN gas))))))) (. .)))
Ninety percent of controlled waste was buried in landfill sites and produced 2 million tons of methane gas.
(ROOT (S (NP (NNS Archaeans)) (VP (VBP produce) (NP (NN methane) (NN gas)) (PP (IN as) (NP (DT a) (NN waste) (NN product)))) (. .)))