( ( ( ( The heating ) ( of ( an ( insulating material ) ) ) ) ( by ( a ( high-frequency ( electric field ) ) ) ) ) . )
(ROOT (NP (NP (DT The) (NN heating)) (PP (IN of) (NP (DT an) (JJ insulating) (NN material))) (PP (IN by) (NP (DT a) (JJ high-frequency) (JJ electric) (NN field))) (. .)))
The heating of an insulating material by a high-frequency electric field .
(ROOT (S (NP (PRP You)) (VP (VBP call) (NP (NP (NNS materials)) (SBAR (WHNP (WDT that)) (S (VP (VBP have) (NP (JJ high) (NN resistance)) (PP (TO to) (NP (JJ electric) (JJ current) (JJ electric) (NNS insulators)))))))) (. .)))