( ( In ( ( the presence ) ( of ( both ( ( steam and ) oxygen ) ) ) ) ) ( , ( ( ( ( ( at ( high temperatures ) ) ( , ( graphite ( forms ( synthesis gas ) ) ) ) ) and ) ( ( with ( the ( water ( gas ( shift reaction ) ) ) ) ) ( ( the ( resultant hydrogen ) ) ( burns explosively ) ) ) ) . ) ) )
(ROOT (S (PP (IN In) (NP (NP (DT the) (NN presence)) (PP (IN of) (NP (DT both) (NN steam) (CC and) (NN oxygen))))) (, ,) (S (PP (IN at) (NP (JJ high) (NNS temperatures))) (, ,) (NP (NN graphite)) (VP (VBZ forms) (NP (NN synthesis) (NN gas)))) (CC and) (S (PP (IN with) (NP (DT the) (NN water) (NN gas) (NN shift) (NN reaction))) (NP (DT the) (NN resultant) (NN hydrogen)) (VP (VBZ burns) (ADVP (RB explosively)))) (. .)))
In the presence of both steam and oxygen, at high temperatures, graphite forms synthesis gas and with the water gas shift reaction the resultant hydrogen burns explosively.
(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)))))) (. .)))