( ( The goal ) ( ( is ( to ( directly ( observe ( how ( ( ( primary particles ) ( emitted ( from ( ( the ( many ( air ( pollution sources ) ) ) ) ( in ( a ( major city ) ) ) ) ) ) ) ( are ( modified ( by ( ( gas-to-particle ( conversion processes ) ) ( in ( the atmosphere ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN goal)) (VP (VBZ is) (S (VP (TO to) (VP (ADVP (RB directly)) (VB observe) (SBAR (WHADVP (WRB how)) (S (NP (NP (JJ primary) (NNS particles)) (VP (VBN emitted) (PP (IN from) (NP (NP (DT the) (JJ many) (NN air) (NN pollution) (NNS sources)) (PP (IN in) (NP (DT a) (JJ major) (NN city))))))) (VP (VBP are) (VP (VBN modified) (PP (IN by) (NP (NP (JJ gas-to-particle) (NN conversion) (NNS processes)) (PP (IN in) (NP (DT the) (NN atmosphere))))))))))))) (. .)))
The goal is to directly observe how primary particles emitted from the many air pollution sources in a major city are modified by gas-to-particle conversion processes in the atmosphere.
(ROOT (S (NP (JJ Primary) (NNS pollutants)) (VP (VBP enter) (NP (DT the) (NN air)) (ADVP (RB directly))) (. .)))