( ( Cigarette smoke ) ( ( contains ( ( ( ( more ( than 4,000 ) ) ( different chemicals ) ) , ) ( ( many ( of which ) ) ( ( ( are ( proven carcinogens ) ) , ) ( while ( ( hundreds ( of others ) ) ( increase ( ( the ( cancer ( causing power ) ) ) ( of carcinogens ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Cigarette) (NN smoke)) (VP (VBZ contains) (NP (NP (QP (JJR more) (IN than) (CD 4,000)) (JJ different) (NNS chemicals)) (, ,) (SBAR (WHNP (DT many) (WHPP (IN of) (WHNP (WDT which)))) (S (VP (VBP are) (NP (VBN proven) (NNS carcinogens)) (, ,) (SBAR (IN while) (S (NP (NP (NNS hundreds)) (PP (IN of) (NP (NNS others)))) (VP (VB increase) (NP (NP (DT the) (NN cancer) (VBG causing) (NN power)) (PP (IN of) (NP (NNS carcinogens)))))))))))) (. .)))
Cigarette smoke contains more than 4,000 different chemicals, many of which are proven carcinogens, while hundreds of others increase the cancer causing power of carcinogens.
(ROOT (S (NP (NNS Cigarettes)) (VP (VBP are) (NP (NP (DT a) (JJ major) (NN source)) (PP (IN of) (NP (NP (NNS carcinogens)) (, ,) (NP (NP (DT a) (NN kind)) (PP (IN of) (NP (NP (NN chemical) (NNS substances)) (VP (VBN linked) (PP (IN with) (NP (NN cancer))))))))))) (. .)))