( ( ( Hydrogen and ) helium ) ( ( are ( the ( ( most abundant ) species ) ) ) . ) )
(ROOT (S (NP (NNP Hydrogen) (CC and) (NNP helium)) (VP (VBP are) (NP (DT the) (ADJP (RBS most) (JJ abundant)) (NN species))) (. .)))
Hydrogen and helium are the most abundant species.
(ROOT (S (NP (NNP Saturn)) (VP (VBZ is) (VP (VBN made) (ADVP (RB mostly)) (PP (IN of) (NP (NN helium) (CC and) (NN hydrogen))))) (. .)))