( ( Types ( of ( radio waves ) ) ) . )
(ROOT (NP (NP (NNS Types)) (PP (IN of) (NP (NN radio) (NNS waves))) (. .)))
Types of radio waves.
(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))) (. .)))