( Light ( ( ( can also ) ( ( ( travel ( at ( ( various speeds ) ( in ( different media ) ) ) ) ) , ) ( producing ( ( a frequency ) ( ( at which ) ( ( the wave ) travels ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Light)) (VP (MD can) (ADVP (RB also)) (VP (VB travel) (PP (IN at) (NP (NP (JJ various) (NNS speeds)) (PP (IN in) (NP (JJ different) (NNS media))))) (, ,) (S (VP (VBG producing) (NP (NP (DT a) (NN frequency)) (SBAR (WHPP (IN at) (WHNP (WDT which))) (S (NP (DT the) (NN wave)) (VP (VBZ travels))))))))) (. .)))
Light can also travel at various speeds in different media, producing a frequency at which the wave travels.
(ROOT (S (NP (JJ Different) (NNS media)) (VP (VBP affect) (NP (NP (DT the) (NN speed)) (PP (IN of) (NP (NN light))))) (. .)))