( ( ( The pull ) ( of gravity ) ) ( ( is ( ( ( ( a force ) ( of attraction ) ) ( -LRB- ( ( called weight ) -RRB- ) ) ) ( between ( two objects ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN pull)) (PP (IN of) (NP (NN gravity)))) (VP (VBZ is) (NP (NP (DT a) (NN force)) (PP (IN of) (NP (NN attraction))) (PRN (-LRB- -LRB-) (VP (VBN called) (NP (NN weight))) (-RRB- -RRB-)) (PP (IN between) (NP (CD two) (NNS objects))))) (. .)))
The pull of gravity is a force of attraction (called weight) between two objects.
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT the) (NN measure)) (PP (IN of) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NP (NN gravity)) (VP (VBG pulling) (PRT (RP down)) (PP (IN on) (NP (DT an) (NN object)))))))))) (. .)))