( ( ( Air ( pollution ( Basic characters ) ) ) ( of ( the ( atmosphere primary ) ) ) ) ( ( vs ( secondary pollutants ) ) ; ) )
(ROOT (S (NP (NP (NNP Air) (NN pollution) (NN Basic) (NNS characters)) (PP (IN of) (NP (DT the) (NN atmosphere) (NN primary)))) (VP (VBP vs) (NP (JJ secondary) (NNS pollutants))) (: ;)))
Air pollution Basic characters of the atmosphere primary vs secondary pollutants;
(ROOT (S (NP (JJ Primary) (NNS pollutants)) (VP (VBP enter) (NP (DT the) (NN air)) (ADVP (RB directly))) (. .)))