( Quarks ( ( are ( ( the ( basic particles ) ) ( that ( combine ( to ( form ( ( protons and ) neutrons ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (NNS Quarks)) (VP (VBP are) (NP (NP (DT the) (JJ basic) (NNS particles)) (SBAR (WHNP (WDT that)) (S (VP (VBP combine) (S (VP (TO to) (VP (VB form) (NP (NNS protons) (CC and) (NNS neutrons)))))))))) (: ;)))
Quarks are the basic particles that combine to form protons and neutrons;
(ROOT (S (NP (NNS Protons) (CC and) (NNS neutrons)) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NP (NNS quarks)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (NP (NP (JJ fundamental) (NNS particles)) (PP (IN of) (NP (NN matter))))))))))) (. .)))