( ( Because ( they ( breathed ( a ( nitrogen-free ( oxygen-neon-argon atmosphere ) ) ) ) ) ) ( , ( decompression ( ( was rapid ) . ) ) ) )
(ROOT (S (SBAR (IN Because) (S (NP (PRP they)) (VP (VBD breathed) (NP (DT a) (JJ nitrogen-free) (JJ oxygen-neon-argon) (NN atmosphere))))) (, ,) (NP (NN decompression)) (VP (VBD was) (ADJP (JJ rapid))) (. .)))
Because they breathed a nitrogen-free oxygen-neon-argon atmosphere, decompression was rapid.
(ROOT (S (NP (NNP Nitrogen) (, ,) (NNP oxygen) (CC and) (NNP argon)) (VP (VBP are) (NP (NP (DT the) (CD three) (JJS most) (JJ common) (NNS elements)) (PP (IN in) (NP (NP (DT the) (NN air)) (SBAR (S (NP (PRP we)) (VP (VB breathe)))))))) (. .)))