( ( ( The burning ) ( of ( fossil fuels ) ) ) ( ( ( releases ( sulfur ( and ( nitrogen oxides ) ) ) ) ( into ( ( ( the atmosphere ) , ) ( which ( are ( converted ( to ( ( ( sulfuric and ) nitric ) acids ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN burning)) (PP (IN of) (NP (JJ fossil) (NNS fuels)))) (VP (VBZ releases) (NP (NN sulfur) (CC and) (NN nitrogen) (NNS oxides)) (PP (IN into) (NP (NP (DT the) (NN atmosphere)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (VP (VBN converted) (PP (TO to) (NP (ADJP (JJ sulfuric) (CC and) (JJ nitric)) (NNS acids)))))))))) (. .)))
The burning of fossil fuels releases sulfur and nitrogen oxides into the atmosphere, which are converted to sulfuric and nitric acids.
(ROOT (S (NP (DT The) (NN element) (NN sulfur)) (VP (VBZ is) (VP (VBN released) (PP (IN into) (NP (DT the) (NN atmosphere))) (PP (IN by) (NP (NP (DT the) (NN burning)) (PP (IN of) (NP (JJ fossil) (NNS fuels))))))) (. .)))