( Matter ( ( can ( be ( ( ( a ( pure ( chemical substance ) ) ) or ) ( ( a mixture ) ( of substances ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Matter)) (VP (MD can) (VP (VB be) (NP (NP (DT a) (JJ pure) (NN chemical) (NN substance)) (CC or) (NP (NP (DT a) (NN mixture)) (PP (IN of) (NP (NNS substances))))))) (. .)))
Matter can be a pure chemical substance or a mixture of substances.
(ROOT (S (NP (NNS Elements)) (VP (VBP are) (NP (NP (JJ pure) (NNS substances)) (SBAR (WHNP (WDT that)) (S (VP (VBP make) (ADVP (RB up) (DT all) (NN matter))))))) (. .)))