( ( The ( gas phase ) ) ( ( includes ( ( ( water vapor ) and ) ( atmospheric air ) ) ) . ) )
(ROOT (S (NP (DT The) (NN gas) (NN phase)) (VP (VBZ includes) (NP (NP (NN water) (NN vapor)) (CC and) (NP (JJ atmospheric) (NN air)))) (. .)))
The gas phase includes water vapor and atmospheric air.
(ROOT (S (NP (NNP Water) (NN vapor)) (VP (VBZ exists) (PP (IN in) (NP (NP (DT the) (NN atmosphere)) (PP (IN as) (NP (DT an) (JJ invisible) (NN gas))))))))
Water vapor exists in the atmosphere as an invisible gas