( ( ( The ( atmospheric nitrogen ) ) ( used ( in ( this process ) ) ) ) ( ( ( ( is inexhaustible ) , ) ( as ( ( ( the ( earth 's ) ) atmosphere ) ( is ( 78 ( percent ( N2 gas ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ atmospheric) (NN nitrogen)) (VP (VBN used) (PP (IN in) (NP (DT this) (NN process))))) (VP (VBZ is) (ADJP (JJ inexhaustible)) (, ,) (SBAR (IN as) (S (NP (NP (DT the) (NN earth) (POS 's)) (NN atmosphere)) (VP (VBZ is) (NP (CD 78) (NN percent) (NN N2) (NN gas)))))) (. .)))
The atmospheric nitrogen used in this process is inexhaustible, as the earth's atmosphere is 78 percent N2 gas.
(ROOT (S (NP (NN Nitrogen) (NN gas)) (VP (VBZ comprises) (NP (NP (QP (RB about) (NNS three-fourths))) (PP (IN of) (NP (NP (NN earth) (POS 's)) (NN atmosphere))))) (. .)))