( Gases ( ( assume ( ( the shapes ) ( of ( their containers ) ) ) ) . ) )
(ROOT (S (NP (NNS Gases)) (VP (VBP assume) (NP (NP (DT the) (NNS shapes)) (PP (IN of) (NP (PRP$ their) (NNS containers))))) (. .)))
Gases assume the shapes of their containers.
(ROOT (S (NP (DT A) (NN gas)) (VP (VBZ assumes) (NP (NP (DT the) (NN shape)) (PP (IN of) (NP (PRP$ its) (NN container))))) (. .)))