( ( ( THE ( EARLY ( SOLAR ( SYSTEM Studies ) ) ) ) ( of ( primitive meteorites ) ) ) ( ( believed ( to ( ( represent ( ( the ( earliest rocks ) ) ( of ( the ( solar ( system lead ) ) ) ) ) ) ( to ( ( an understanding ) ( of ( how ( ( ( the ( ( gas and ) dust ) ) ( of ( the ( pre-planetary ( solar system ) ) ) ) ) ( evolved ( to ( form ( terrestrial planets ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT THE) (NNP EARLY) (NNP SOLAR) (NNP SYSTEM) (NNP Studies)) (PP (IN of) (NP (JJ primitive) (NNS meteorites)))) (VP (VBD believed) (S (VP (TO to) (VP (VB represent) (NP (NP (DT the) (JJS earliest) (NNS rocks)) (PP (IN of) (NP (DT the) (JJ solar) (NN system) (NN lead)))) (PP (TO to) (NP (NP (DT an) (NN understanding)) (PP (IN of) (SBAR (WHADVP (WRB how)) (S (NP (NP (DT the) (NN gas) (CC and) (NN dust)) (PP (IN of) (NP (DT the) (JJ pre-planetary) (JJ solar) (NN system)))) (VP (VBD evolved) (S (VP (TO to) (VP (VB form) (NP (JJ terrestrial) (NNS planets))))))))))))))) (. .)))
THE EARLY SOLAR SYSTEM Studies of primitive meteorites believed to represent the earliest rocks of the solar system lead to an understanding of how the gas and dust of the pre-planetary solar system evolved to form terrestrial planets.
(ROOT (S (NP (NP (NNS Meteorites)) (, ,) (VP (VBN formed) (PP (IN of) (NP (NN split) (NNS asteroids) (CC or) (NN planetary) (NNS rocks)))) (, ,)) (VP (VBP provide) (NP (NP (NNS clues)) (PP (IN about) (NP (PRP$ our) (JJ solar) (NN system))))) (. .)))