( ( ( and combinations ) ( of ( ( ( increases and ) decreases ) ( in pressure ) ) ) ) . )
(ROOT (NP (NP (QP (CC and) (CD combinations))) (PP (IN of) (NP (NP (NNS increases) (CC and) (NNS decreases)) (PP (IN in) (NP (NN pressure))))) (. .)))
and combinations of increases and decreases in pressure.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NN gas) (NNS particles)) (VP (VB heat) (PRT (RP up))))) (, ,) (NP (NN pressure)) (VP (VBP increase)) (. .)))