( Right ( , ( or ( ( they ( can ( ( amplify ( each other ) ) ( if ( ( ( ( ( two ( high points ) ) ( -LRB- ( crests -RRB- ) ) ) or ) ( ( two ( low points ) ) ( -LRB- ( troughs -RRB- ) ) ) ) ( happen ( to meet ) ) ) ) ) ) ) . ) ) ) )
(ROOT (FRAG (NP (NNP Right)) (, ,) (CC or) (S (NP (PRP they)) (VP (MD can) (VP (VB amplify) (NP (DT each) (JJ other)) (SBAR (IN if) (S (NP (NP (NP (CD two) (JJ high) (NNS points)) (PRN (-LRB- -LRB-) (NP (NNS crests)) (-RRB- -RRB-))) (CC or) (NP (NP (CD two) (JJ low) (NNS points)) (PRN (-LRB- -LRB-) (NP (NNS troughs)) (-RRB- -RRB-)))) (VP (VBP happen) (S (VP (TO to) (VP (VB meet)))))))))) (. .)))
Right, or they can amplify each other if two high points ( crests ) or two low points ( troughs ) happen to meet.
(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)))))) (. .)))