( ( ( The ( chief components ) ) ( of ( ( the ( Earth 's ) ) atmosphere ) ) ) ( ( are ( ( nitrogen and ) oxygen ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ chief) (NNS components)) (PP (IN of) (NP (NP (DT the) (NN Earth) (POS 's)) (NN atmosphere)))) (VP (VBP are) (NP (NN nitrogen) (CC and) (NN oxygen))) (. .)))
The chief components of the Earth's atmosphere are nitrogen and oxygen.
(ROOT (S (NP (NN Oxygen) (CC and) (NN nitrogen)) (VP (VBP make) (PRT (RP up)) (NP (NP (JJS most)) (PP (IN of) (NP (NP (DT the) (NN earth) (POS 's)) (NN atmosphere))))) (. .)))
Oxygen and nitrogen make up most of the earth's atmosphere.