( ( As ( ( the temperature ) ( of ( the ( ( liquid ( in ( a thermometer ) ) ) increases ) ) ) ) ) ( , ( ( its volume ) ( increases . ) ) ) )
(ROOT (S (PP (IN As) (NP (NP (DT the) (NN temperature)) (PP (IN of) (NP (DT the) (ADJP (JJ liquid) (PP (IN in) (NP (DT a) (NN thermometer)))) (NNS increases))))) (, ,) (NP (PRP$ its) (NN volume)) (VP (VBZ increases)) (. .)))
As the temperature of the liquid in a thermometer increases, its volume increases.
(ROOT (S (PP (IN As) (NP (NN temperature) (NNS increases))) (, ,) (NP (NN volume)) (VP (VBZ increases)) (. .)))