( ( ( The volume ) ( of ( ( a ( given amount ) ) ( of ( ( gas increases ) ( as ( ( the pressure ) ( surrounding it ) ) ) ) ) ) ) ) ( decreases . ) )
(ROOT (S (NP (NP (DT The) (NN volume)) (PP (IN of) (NP (NP (DT a) (VBN given) (NN amount)) (PP (IN of) (NP (NP (NN gas) (NNS increases)) (PP (IN as) (NP (NP (DT the) (NN pressure)) (VP (VBG surrounding) (NP (PRP it)))))))))) (VP (VBZ decreases)) (. .)))
The volume of a given amount of gas increases as the pressure surrounding it decreases.
(ROOT (S (PP (IN From) (NP (NP (NNS observations)) (ADJP (RB as) (JJ simple) (PP (IN as) (S (VP (VBG blowing) (PRT (RP up)) (NP (DT a) (NN balloon)))))))) (, ,) (NP (PRP it)) (VP (VBZ is) (ADJP (JJ clear)) (SBAR (IN that) (S (S (VP (VBG increasing) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NN gas)))))) (VP (VBZ increases) (NP (DT the) (NN volume)))))) (. .)))