( ( ( ( ( ( ( Protons and ) neutrons ) ( are ( made ( of ( three quarks ) ) ) ) ) , ) and ) ( mesons ( , ( ( like pions ) ( , ( are ( made ( of ( quark-antiquark ( ( pairs -LRB- ) ( see Fig ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (NNS Protons) (CC and) (NNS neutrons)) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (CD three) (NNS quarks)))))) (, ,) (CC and) (S (NP (NNS mesons)) (, ,) (PP (IN like) (NP (NNS pions))) (, ,) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NP (NN quark-antiquark)) (SBAR (S (VP (VBD pairs) (-LRB- -LRB-) (SBAR (VB see) (S (VP (VBN Fig)))))))))))) (. .)))
Protons and neutrons are made of three quarks, and mesons, like pions, are made of quark-antiquark pairs ( see Fig.
(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))))) (. .)))