( ( Carbon dioxide ) ( ( was ( analyzed ( for ( ( ( ( ( the ( stable ( isotope carbon-13 ) ) ) ( -LRB- ( ( 13 C ) -RRB- ) ) ) and ) ( the ( radioactive ( isotope carbon-14 ) ) ) ) ( -LRB- ( ( 14 C ) -RRB- ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Carbon) (NN dioxide)) (VP (VBD was) (VP (VBN analyzed) (PP (IN for) (NP (NP (DT the) (JJ stable) (NN isotope) (NN carbon-13)) (PRN (-LRB- -LRB-) (NP (QP (CD 13) (CD C))) (-RRB- -RRB-)) (CC and) (NP (DT the) (JJ radioactive) (NN isotope) (NN carbon-14)) (PRN (-LRB- -LRB-) (NP (QP (CD 14) (CD C))) (-RRB- -RRB-)))))) (. .)))
Carbon dioxide was analyzed for the stable isotope carbon-13 ( 13 C) and the radioactive isotope carbon-14 ( 14 C).
(ROOT (S (NP (NP (NNP Carbon) (CD 14) (NN isotope)) (PP (IN of) (NP (NN carbon)))) (VP (VBZ is) (ADVP (RB typically)) (VP (VBN used) (PP (TO to) (NP (NN date) (JJ ancient) (NNS items))))) (. .)))