( Radio ( ( waves ( ( electromagnetic waves ) ( that ( can ( ( ( ( ( travel across ) space ) unrestrictedly ) , ) ( in ( ( the ( frequency spectrum ) ) ( from ( ( 9 KHz ) ( to ( 3,000 GHz ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Radio)) (VP (VBZ waves) (NP (NP (JJ electromagnetic) (NNS waves)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (VP (VB travel) (PRT (RP across)) (NP (NN space)) (ADVP (RB unrestrictedly)) (, ,) (PP (IN in) (NP (NP (DT the) (NN frequency) (NN spectrum)) (PP (IN from) (NP (NP (CD 9) (NNS KHz)) (PP (TO to) (NP (CD 3,000) (NNS GHz))))))))))))) (. .)))
Radio waves electromagnetic waves that can travel across space unrestrictedly, in the frequency spectrum from 9 KHz to 3,000 GHz.
(ROOT (S (NP (NNP Am) (NN radio) (NNS waves)) (VP (VBP exist) (PRT (RP in)) (NP (DT the) (ADJP (QP (CD 540) (TO to) (CD 1600))) (NN khz) (NN frequency) (NN range))) (. .)))