( ( ( ( Pneumonia , ) ( which ( ( is ( ( an accumulation ) ( of ( fluids ( in ( the alveoli ) ) ) ) ) ) ( so ( that ( ( exchange ( of oxygen ) ) ( is impossible ) ) ) ) ) ) ) , ) ( ( can ( be ( ( brought on ) ( by ( getting ( ( an aspirin ) ( caught ( in ( the windpipe ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Pneumonia)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (NP (NP (DT an) (NN accumulation)) (PP (IN of) (NP (NP (NNS fluids)) (PP (IN in) (NP (DT the) (NNS alveoli)))))) (SBAR (RB so) (IN that) (S (NP (NP (NN exchange)) (PP (IN of) (NP (NN oxygen)))) (VP (VBZ is) (ADJP (JJ impossible)))))))) (, ,)) (VP (MD can) (VP (VB be) (VP (VBN brought) (PRT (RP on)) (PP (IN by) (S (VP (VBG getting) (NP (NP (DT an) (NN aspirin)) (VP (VBN caught) (PP (IN in) (NP (DT the) (NN windpipe))))))))))) (. .)))
Pneumonia, which is an accumulation of fluids in the alveoli so that exchange of oxygen is impossible, can be brought on by getting an aspirin caught in the windpipe.
(ROOT (S (NP (DT The) (NN term) (NN pneumonia)) (VP (VBZ is) (NP (NP (DT the) (NN name)) (PP (IN of) (NP (NP (DT the) (NN disease)) (SBAR (WHADVP (WRB where)) (S (NP (NP (DT some)) (PP (IN of) (NP (NP (DT the) (NNS alveoli)) (PP (IN of) (NP (DT the) (NNS lungs)))))) (VP (VBP fill) (PP (IN with) (NP (NN fluid))) (SBAR (IN so) (S (NP (PRP they)) (VP (MD can) (ADVP (RB no) (RB longer)) (VP (VB exchange) (NP (NN gas))))))))))))) (. .)))