( ( Episode 4 ) ( - ( ( ( ( ( ( ( Earth 's ) ( Air ( NASA ( scientist ( Joel Levine ) ) ) ) ) , ) ( Langley ( Research Center ) ) ) , ) ( describes ( ( ( ( the composition ) ( of ( ( Earth 's ) atmosphere ) ) ) and ) ( ( its changes ) ( over ( geologic time ) ) ) ) ) ) . ) ) )
(ROOT (X (NP (NN Episode) (CD 4)) (: -) (S (NP (NP (NP (NNP Earth) (POS 's)) (NNP Air) (NNP NASA) (NNP scientist) (NNP Joel) (NNP Levine)) (, ,) (NP (NNP Langley) (NNP Research) (NNP Center)) (, ,)) (VP (VBZ describes) (NP (NP (NP (DT the) (NN composition)) (PP (IN of) (NP (NP (NNP Earth) (POS 's)) (NN atmosphere)))) (CC and) (NP (NP (PRP$ its) (NNS changes)) (PP (IN over) (NP (JJ geologic) (NN time))))))) (. .)))
Episode 4 - Earth's Air NASA scientist Joel Levine, Langley Research Center, describes the composition of Earth's atmosphere and its changes over geologic time.
(ROOT (S (SBAR (WHADVP (WRB How)) (S (NP (NN ice) (NNS cores)) (VP (VBP are) (ADJP (JJ important) (PP (TO to) (NP (NP (DT the) (NN study)) (PP (IN of) (NP (JJ geologic) (NN history))))))))) (VP (VBZ is) (ADVP (RBS best)) (VP (VBN described) (SBAR (IN as) (S (NP (PRP they)) (VP (VBP contain) (NP (NN evidence) (NN showing) (NNS changes)) (PP (IN in) (NP (NP (DT the) (JJ atmospheric) (NN composition)) (PP (IN over) (NP (NN time)))))))))) (. .)))