( thus ( , ( there ( ( are ( ( a total ) ( of ( ( ( six leptons ) and ) ( six quarks ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB thus)) (, ,) (NP (EX there)) (VP (VBP are) (NP (NP (DT a) (NN total)) (PP (IN of) (NP (NP (CD six) (NNS leptons)) (CC and) (NP (CD six) (NNS quarks)))))) (. .)))
thus, there are a total of six leptons and six quarks.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD six) (NNS types)) (PP (IN of) (NP (NNS leptons))))) (. .)))