( ( Most gas ) ( ( moves ( under ( contract ( of ( ( ( one sort ) or ) another ) ) ) ) ) . ) )
(ROOT (S (NP (JJS Most) (NN gas)) (VP (VBZ moves) (PP (IN under) (NP (NP (NN contract)) (PP (IN of) (NP (NP (CD one) (NN sort)) (CC or) (NP (DT another))))))) (. .)))
Most gas moves under contract of one sort or another.
(ROOT (S (PP (IN Within) (NP (DT a) (NN substance))) (, ,) (NP (NP (NNS atoms)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBP collide) (ADVP (RB frequently))) (CC and) (VP (VBP move) (ADVP (RB independently)) (PP (IN of) (NP (CD one) (DT another)))))))) (VP (VBP are) (ADJP (ADJP (RBS most) (JJ likely)) (PP (IN in) (NP (DT a) (NN gas)))))))