( ( A ( medium-energy ( beta particle ) ) ) ( ( travels ( about ( ( ( ( one meter ) ( in air ) ) and ) ( ( one millimeter ) ( in ( body tissue ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (JJ medium-energy) (NN beta) (NN particle)) (VP (VBZ travels) (PP (IN about) (NP (NP (NP (CD one) (NN meter)) (PP (IN in) (NP (NN air)))) (CC and) (NP (NP (CD one) (NN millimeter)) (PP (IN in) (NP (NN body) (NN tissue))))))) (. .)))
A medium-energy beta particle travels about one meter in air and one millimeter in body tissue.
(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))))) (. .)))