( ( Once inhaled ) ( , ( ( pepper spray ) ( ( ( ( inflames ( your ( respiratory tract ) ) ) and ) ( swells ( mucous ( membranes ( that ( ( line breathing ) ( ( passages , ) ( making ( it ( difficult ( to breath ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Once) (S (VP (VBD inhaled)))) (, ,) (NP (NN pepper) (NN spray)) (VP (VP (VBZ inflames) (NP (PRP$ your) (JJ respiratory) (NN tract))) (CC and) (VP (VBZ swells) (SBAR (S (NP (NNS mucous)) (VP (VBZ membranes) (SBAR (IN that) (S (NP (NN line) (NN breathing)) (VP (VBZ passages) (, ,) (S (VP (VBG making) (S (NP (PRP it)) (ADJP (JJ difficult) (PP (TO to) (NP (NN breath))))))))))))))) (. .)))
Once inhaled, pepper spray inflames your respiratory tract and swells mucous membranes that line breathing passages, making it difficult to breath.
(ROOT (S (NP (NNP Narrow) (NN air) (NNS passages)) (VP (VBP make) (S (VP (VBG breathing) (ADJP (JJ difficult) (RB due) (S (VP (TO to) (VP (VB respiratory) (NP (NN system) (NN disease))))))))) (. .)))