( Air ( ( is ( ( comprised ( of ( ( a mixture ) ( of gases ) ) ) ) ( -- ( mainly ( ( ( ( ( nitrogen , ) oxygen ) , ) and ) argon ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Air)) (VP (VBZ is) (VP (VBN comprised) (PP (IN of) (NP (NP (DT a) (NN mixture)) (PP (IN of) (NP (NNS gases))))) (PRN (: --) (ADVP (RB mainly)) (NP (NP (NN nitrogen)) (, ,) (NP (NN oxygen)) (, ,) (CC and) (NP (NNP argon)))))) (. .)))
Air is comprised of a mixture of gases--mainly nitrogen, oxygen, and argon.
(ROOT (S (NP (NNP Nitrogen) (, ,) (NNP oxygen) (CC and) (NNP argon)) (VP (VBP are) (NP (NP (DT the) (CD three) (JJS most) (JJ common) (NNS elements)) (PP (IN in) (NP (NP (DT the) (NN air)) (SBAR (S (NP (PRP we)) (VP (VB breathe)))))))) (. .)))