( ( ( The leaves ) ( of ( a ( ( positively charged ) electroscope ) ) ) ) ( ( are separated ) . ) )
(ROOT (S (NP (NP (DT The) (NNS leaves)) (PP (IN of) (NP (DT a) (ADJP (ADVP (RB positively)) (VBN charged)) (NN electroscope)))) (VP (VBP are) (ADJP (JJ separated))) (. .)))
The leaves of a positively charged electroscope are separated.
(ROOT (S (NP (DT A) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN electroscope)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB study) (NP (NN charge))))))) (. .)))