( ( Each ( water molecule ) ) ( ( contains ( ( ( ( ( 3 atoms ) , ) ( 2 ( of hydrogen ) ) ) and ) ( 1 ( of oxygen ) ) ) ) . ) )
(ROOT (S (NP (DT Each) (NN water) (NN molecule)) (VP (VBZ contains) (NP (NP (CD 3) (NNS atoms)) (, ,) (NP (NP (CD 2)) (PP (IN of) (NP (NN hydrogen)))) (CC and) (NP (NP (CD 1)) (PP (IN of) (NP (NN oxygen)))))) (. .)))
Each water molecule contains 3 atoms, 2 of hydrogen and 1 of oxygen.
(ROOT (S (NP (NNP Water)) (VP (VBZ contains) (NP (CD 3) (NNS atoms))) (. .)))
Water contains 3 atoms.