( ( ( The speed ) ( of ( ( sound changes ) ( as ( altitude ( and ( air temperature ) ) ) ) ) ) ) ( change . ) )
(ROOT (S (NP (NP (DT The) (NN speed)) (PP (IN of) (NP (NP (JJ sound) (NNS changes)) (PP (IN as) (NP (NN altitude) (CC and) (NN air) (NN temperature)))))) (VP (VBP change)) (. .)))
The speed of sound changes as altitude and air temperature change.
(ROOT (S (NP (NNP Air) (NN temperature)) (VP (VBZ changes) (PP (IN as) (NP (NN altitude) (NNS increases)))) (. .)))