( ( Natural gas ) ( ( is ( one ( of ( ( the ( ( most dangerous ) substances ) ) ( in ( the home ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Natural) (NN gas)) (VP (VBZ is) (NP (NP (CD one)) (PP (IN of) (NP (NP (DT the) (ADJP (RBS most) (JJ dangerous)) (NNS substances)) (PP (IN in) (NP (DT the) (NN home))))))) (. .)))
Natural gas is one of the most dangerous substances in the home.
(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)))))))