( She ( also ( ( invented ( ( the Geiger ) ( counter ( to ( measure radioactivity ) ) ) ) ) . ) ) )
(ROOT (S (NP (PRP She)) (ADVP (RB also)) (VP (VBD invented) (SBAR (S (NP (DT the) (NNP Geiger)) (VP (VBP counter) (S (VP (TO to) (VP (VB measure) (NP (NN radioactivity))))))))) (. .)))
She also invented the Geiger counter to measure radioactivity.
(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))))))) (. .)))