( ( The ( simplest ( carbon-containing molecules ) ) ) ( ( ( are ( ( ( ( the hydrocarbons ) , ) ( which ( contain ( ( carbon and ) hydrogen ) ) ) ) , ) ) ( although ( they ( sometimes ( contain ( ( other elements ) ( in ( functional groups ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJS simplest) (JJ carbon-containing) (NNS molecules)) (VP (VBP are) (NP (NP (DT the) (NNS hydrocarbons)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP contain) (NP (NN carbon) (CC and) (NN hydrogen))))) (, ,)) (SBAR (IN although) (S (NP (PRP they)) (ADVP (RB sometimes)) (VP (VBP contain) (NP (NP (JJ other) (NNS elements)) (PP (IN in) (NP (JJ functional) (NNS groups)))))))) (. .)))
The simplest carbon-containing molecules are the hydrocarbons, which contain carbon and hydrogen, although they sometimes contain other elements in functional groups.
(ROOT (S (SBAR (IN Although) (S (NP (PRP they)) (VP (VBP differ) (ADVP (RB vastly)) (PP (IN in) (NP (NNS hardness)))))) (, ,) (NP (NP (NN pencil) (NN lead)) (CC and) (NP (NNS diamonds))) (DT both) (VP (VBP contain) (NP (NN carbon))) (. .)))