( ( ( ( ( ( ( Ozone depletion ) , ) ( acid rain ) ) , ) and ) ( global warming ) ) ( ( are ( ( three aspects ) ( of ( ( air pollution ) ( commonly ( talked ( about today ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NN Ozone) (NN depletion)) (, ,) (NP (JJ acid) (NN rain)) (, ,) (CC and) (NP (JJ global) (NN warming))) (VP (VBP are) (NP (NP (CD three) (NNS aspects)) (PP (IN of) (NP (NP (NN air) (NN pollution)) (VP (ADVP (RB commonly)) (VBN talked) (PP (IN about) (NP (NN today)))))))) (. .)))
Ozone depletion , acid rain, and global warming are three aspects of air pollution commonly talked about today.
(ROOT (S (NP (NNP Air) (NN pollution)) (VP (VBZ causes) (NP (NP (JJ acid) (NN rain)) (, ,) (NP (NN ozone) (NN depletion)) (, ,) (CC and) (NP (JJ global) (NN warming)))) (. .)))