( ( ( ( Electrons , ) ( proton ( , ( neutron ( , ( meson ( , ( boson ( , gluon ) ) ) ) ) ) ) ) ) , ) ( quark . ) )
(ROOT (S (NP (NP (NNS Electrons)) (, ,) (NP (NN proton) (, ,) (NN neutron) (, ,) (NN meson) (, ,) (NN boson) (, ,) (NN gluon)) (, ,)) (VP (VBP quark)) (. .)))
Electrons, proton, neutron, meson, boson, gluon, quark.
(ROOT (S (NP (NP (DT The) (CD two) (JJ main) (JJ fundamental) (NNS particles)) (SBAR (WHNP (WDT that)) (S (VP (VBP make) (PRT (RP up)) (NP (NNS neutrons)))))) (VP (VBP are) (NP (NNS quarks) (CC and) (NNS gluons))) (. .)))