( ( See ( ( ( ozone precursors ) , ) ( ( stratosphere , ) atmosphere ) ) ) . )
(ROOT (S (VP (VB See) (NP (NP (NN ozone) (NNS precursors)) (, ,) (NP (NP (NN stratosphere)) (, ,) (NP (NN atmosphere))))) (. .)))
See ozone precursors , stratosphere , atmosphere .
(ROOT (S (NP (DT The) (NN stratosphere)) (VP (VBZ is) (NP (DT the) (NN heat) (NN source))) (. .)))