( ( ( ( The distance ) ( between ( ( ( a crest ) and ) ( the ( next crest ) ) ) ) ) ( -LRB- ( or ( ( ( ( a trough ) and ) ( the ( next trough ) ) ) -RRB- ) ) ) ) ( ( is ( called ( a wavelength ) ) ) . ) )
(ROOT (S (NP (NP (NP (DT The) (NN distance)) (PP (IN between) (NP (NP (DT a) (NN crest)) (CC and) (NP (DT the) (JJ next) (NN crest))))) (PRN (-LRB- -LRB-) (CC or) (NP (NP (DT a) (NN trough)) (CC and) (NP (DT the) (JJ next) (NN trough))) (-RRB- -RRB-))) (VP (VBZ is) (VP (VBN called) (NP (DT a) (NN wavelength)))) (. .)))
The distance between a crest and the next crest (or a trough and the next trough) is called a wavelength .
(ROOT (S (NP (PRP You)) (VP (VBP call) (SBAR (S (NP (NP (DT the) (ADJP (JJ high) (CC and) (JJ low)) (NNS points)) (PP (IN of) (NP (JJ transverse) (NNS waves)))) (VP (VP (VBZ crests)) (CC and) (VP (VBZ troughs)))))) (. .)))