( They ( ( can ( travel ( through ( hundreds ( of ( ( ( meters ( of air ) ) and ) ( ( the walls ) ( of ( ordinary houses ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (MD can) (VP (VB travel) (PP (IN through) (NP (NP (NNS hundreds)) (PP (IN of) (NP (NP (NP (NNS meters)) (PP (IN of) (NP (NN air)))) (CC and) (NP (NP (DT the) (NNS walls)) (PP (IN of) (NP (JJ ordinary) (NNS houses)))))))))) (. .)))
They can travel through hundreds of meters of air and the walls of ordinary houses.
(ROOT (S (NP (JJ Meter) (JJ much) (NN distance)) (VP (MD can) (VP (VB beta) (NP (JJ particles) (NN travel)) (PP (IN through) (NP (NN air))))) (. .)))