( ( ( ( ( ( The top ) ( of ( the wave ) ) ) ( is ( called ( the crest ) ) ) ) and ) ( ( the bottom ) ( is ( called ( the trough ) ) ) ) ) . )
(ROOT (S (S (NP (NP (DT The) (NN top)) (PP (IN of) (NP (DT the) (NN wave)))) (VP (VBZ is) (VP (VBN called) (NP (DT the) (NN crest))))) (CC and) (S (NP (DT the) (NN bottom)) (VP (VBZ is) (VP (VBN called) (NP (DT the) (NN trough))))) (. .)))
The top of the wave is called the crest and the bottom is called the trough.
(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)))))) (. .)))