( Heat ( ( ( ( expands things ) , ) ( while ( cold contracts ) ) ) . ) )
(ROOT (S (NP (NNP Heat)) (VP (VBZ expands) (NP (NNS things)) (, ,) (PP (IN while) (NP (JJ cold) (NNS contracts)))) (. .)))
Heat expands things, while cold contracts.
(ROOT (S (NP (NP (DT The) (NN liquid)) (PP (IN in) (NP (DT a) (NN thermometer)))) (VP (VP (VBZ expands)) (CC or) (VP (VBZ contracts) (S (VP (TO to) (VP (VB respond) (PP (TO to) (NP (NN heat) (CC or) (NN cold)))))))) (. .)))