( ( When ( ( ( ( ( a gas ) , ) ( usually air ) ) , ) ( is introduced ) ) ) ( , ( it ( ( ( ( combines ( with ( the ( electrical current ) ) ) ) ( to ( create ( a ( high ( temperature ( plasma arc ) ) ) ) ) ) ) ( -LRB- ( ( plasma ( ( ( is ( ( a state ) ( of matter ) ) ) , ) ( unlike ( solid ( , ( ( liquid or ) gas ) ) ) ) ) ) -RRB- ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (DT a) (NN gas)) (, ,) (NP (RB usually) (NN air)) (, ,)) (VP (VBZ is) (VP (VBN introduced))))) (, ,) (NP (PRP it)) (VP (VBZ combines) (PP (IN with) (NP (DT the) (JJ electrical) (NN current))) (S (VP (TO to) (VP (VB create) (NP (DT a) (JJ high) (NN temperature) (NN plasma) (NN arc))))) (PRN (-LRB- -LRB-) (S (NP (NN plasma)) (VP (VBZ is) (NP (NP (DT a) (NN state)) (PP (IN of) (NP (NN matter)))) (, ,) (PP (IN unlike) (NP (JJ solid) (, ,) (NN liquid) (CC or) (NN gas))))) (-RRB- -RRB-))) (. .)))
When a gas, usually air, is introduced, it combines with the electrical current to create a high temperature plasma arc (plasma is a state of matter, unlike solid, liquid or gas).
(ROOT (S (NP (NNP Plasma)) (VP (VBZ completes) (NP (NP (DT the) (NN list)) (: :) (NP (ADJP (ADJP (JJ solid)) (, ,) (ADJP (JJ liquid)) (, ,)) (NN gas)))) (. .)))