( ( ( The inside ) ( of Saturn ) ) ( ( ( is probably ) ( ( ( ( a core ) ( of ( iron ( , ( nickel ( , ( silicon ( and ( oxygen compounds ) ) ) ) ) ) ) ) ) , ) ( surrounded ( by ( ( ( ( ( ( a ( deep layer ) ) ( of ( ( ( ( metallic hydrogen ) , ) then ) ( ( a layer ) ( of ( liquid ( hydrogen ( and ( liquid helium ) ) ) ) ) ) ) ) ) and ) finally ) , ) ( an ( outer ( gaseous layer ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN inside)) (PP (IN of) (NP (NNP Saturn)))) (VP (VBZ is) (ADVP (RB probably)) (NP (NP (DT a) (NN core)) (PP (IN of) (NP (NN iron) (, ,) (NN nickel) (, ,) (NN silicon) (CC and) (NN oxygen) (NNS compounds))) (, ,) (VP (VBN surrounded) (PP (IN by) (NP (NP (NP (DT a) (JJ deep) (NN layer)) (PP (IN of) (NP (NP (JJ metallic) (NN hydrogen)) (, ,) (ADVP (RB then)) (NP (NP (DT a) (NN layer)) (PP (IN of) (NP (JJ liquid) (NN hydrogen) (CC and) (NN liquid) (NNS helium))))))) (CC and) (ADVP (RB finally)) (, ,) (NP (DT an) (JJ outer) (NNS gaseous) (NN layer))))))) (. .)))
The inside of Saturn is probably a core of iron, nickel, silicon and oxygen compounds, surrounded by a deep layer of metallic hydrogen, then a layer of liquid hydrogen and liquid helium and finally, an outer gaseous layer.
(ROOT (S (NP (DT The) (JJ outer) (NN core)) (VP (VBZ is) (VP (VBN made) (PP (IN of) (NP (JJ liquid) (NN metal))))) (. .)))