( ( ( ( Each proton ) and ) ( each neutron ) ) ( ( contains ( three quarks ) ) . ) )
(ROOT (S (NP (NP (DT Each) (NN proton)) (CC and) (NP (DT each) (NN neutron))) (VP (VBZ contains) (NP (CD three) (NNS quarks))) (. .)))
Each proton and each neutron contains three quarks.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD three) (NNS quarks)) (PP (IN in) (NP (DT each) (NN proton) (CC and) (NN neutron))))) (. .)))