( ( In general ) ( , ( ( radioactive substances ) ( ( can ( be ( measured ( using ( a ( Geiger counter ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NN general))) (, ,) (NP (JJ radioactive) (NNS substances)) (VP (MD can) (VP (VB be) (VP (VBN measured) (S (VP (VBG using) (NP (DT a) (NNP Geiger) (NN counter))))))) (. .)))
In general, radioactive substances can be measured using a Geiger counter.
(ROOT (S (NP (NP (DT The) (`` `) (NN counting) ('' ') (NN instrument)) (NP (NN geiger) (NN counter))) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN radioactivity))))))) (. .)))