( • ( ( ( `` ( ( ( high ( sulfur ( dioxide concentration ) ) ) ( in ( the ( waste gas ) ) ) ) '' ) ) -- ) ( ( ( the use ) ( of ( oxygen enrichment ) ) ) ( ( ( ( gives ( the ( ISASMELT plants ) ) ) ( ( high ( sulfur ( dioxide concentrations ) ) ) ( in ( the ( waste ( gas stream ) ) ) ) ) ) , ) ( making ( ( acid plants ) ( cheaper ( to ( ( build and ) operate ) ) ) ) ) ) ) ) )
(ROOT (S (VP (VB •) (FRAG (NP (NP (`` ``) (NP (JJ high) (NN sulfur) (NN dioxide) (NN concentration)) (PP (IN in) (NP (DT the) (NN waste) (NN gas))) ('' '')) (: --) (S (NP (NP (DT the) (NN use)) (PP (IN of) (NP (NN oxygen) (NN enrichment)))) (VP (VBZ gives) (NP (DT the) (JJ ISASMELT) (NNS plants)) (NP (NP (JJ high) (NN sulfur) (NN dioxide) (NNS concentrations)) (PP (IN in) (NP (DT the) (NN waste) (NN gas) (NN stream)))) (, ,) (S (VP (VBG making) (S (NP (JJ acid) (NNS plants)) (ADJP (JJR cheaper) (S (VP (TO to) (VP (VB build) (CC and) (VB operate)))))))))))))))
• "high sulfur dioxide concentration in the waste gas" – the use of oxygen enrichment gives the ISASMELT plants high sulfur dioxide concentrations in the waste gas stream, making acid plants cheaper to build and operate
(ROOT (S (NP (NN Oxygen) (NN gas)) (VP (VBZ is) (VP (VBN given) (PRT (RP off)) (PP (IN by) (NP (NNS plants))))) (. .)))