( Jupiter ( ( ( ( is ( a ( big ( gas bag ) ) ) ) , ) ( with ( a ( ( relatively low ) density ) ) ) ) . ) )
(ROOT (S (NP (NNP Jupiter)) (VP (VBZ is) (NP (DT a) (JJ big) (NN gas) (NN bag)) (, ,) (PP (IN with) (NP (DT a) (ADJP (RB relatively) (JJ low)) (NN density)))) (. .)))
Jupiter is a big gas bag, with a relatively low density.
(ROOT (S (NP (NNS Gases)) (VP (VBP have) (NP (DT the) (JJS lowest) (NN density))) (. .)))