( ( The ( compressed air ) ) ( ( is ( ( ( heated and ) expanded ) ( to ( increase pressure ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ compressed) (NN air)) (VP (VBZ is) (VP (VBN heated) (CC and) (VBN expanded) (PP (TO to) (NP (NN increase) (NN pressure))))) (. .)))
The compressed air is heated and expanded to increase pressure.
(ROOT (S (SBAR (IN As) (S (NP (DT a) (NN diver)) (VP (VBZ descends)))) (, ,) (NP (NP (DT the) (NN increase)) (PP (IN in) (NP (NN pressure)))) (VP (VBZ causes) (NP (NP (DT the) (NN body) (POS 's)) (NN air) (NNS pockets)) (PP (IN in) (NP (NP (DT the) (NNS ears) (CC and) (NNS lungs)) (PP (TO to) (NP (NNS compress)))))) (. .)))