( ( ( The ( earth 's ) ) atmosphere ) ( ( ( consists primarily ) ( of ( ( oxygen and ) nitrogen ) ) ) ; ) )
(ROOT (S (NP (NP (DT The) (NN earth) (POS 's)) (NN atmosphere)) (VP (VBZ consists) (ADVP (RB primarily)) (PP (IN of) (NP (NN oxygen) (CC and) (NN nitrogen)))) (: ;)))
The earth's atmosphere consists primarily of oxygen and nitrogen;
(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.