( ( Return ( to ( Table ( of ( ( Contents Sources ) ( of ( Hydrogen ( Sulfide ( Hydrogen ( sulfide gas ) ) ) ) ) ) ) ) ) ) ( ( is ( formed ( from ( decomposing ( ( ( ( underground deposits ) ( of ( organic matter ) ) ) , ) ( such ( as ( decaying ( plant material ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NN Return)) (PP (TO to) (NP (NP (NNP Table)) (PP (IN of) (NP (NP (NNP Contents) (NNS Sources)) (PP (IN of) (NP (NNP Hydrogen) (NNP Sulfide) (NNP Hydrogen) (JJ sulfide) (NN gas)))))))) (VP (VBZ is) (VP (VBN formed) (PP (IN from) (S (VP (VBG decomposing) (NP (NP (JJ underground) (NNS deposits)) (PP (IN of) (NP (JJ organic) (NN matter))) (, ,) (PP (JJ such) (IN as) (S (VP (VBG decaying) (NP (NN plant) (NN material))))))))))) (. .)))
Return to Table of Contents Sources of Hydrogen Sulfide Hydrogen sulfide gas is formed from decomposing underground deposits of organic matter, such as decaying plant material.
(ROOT (S (NP (NNP Hydrogen)) (VP (VBZ is) (PP (IN in) (NP (NP (NN gas) (NN form)) (PP (IN at) (NP (NN room) (NN temperature)))))) (. .)))