( Electromagnetic waves )
(ROOT (NP (JJ Electromagnetic) (NNS waves)))
Electromagnetic waves
(ROOT (S (SBAR (IN Because) (S (NP (NP (DT the) (NNS fields)) (SBAR (WHNP (WDT that)) (S (VP (VBP make) (PRT (RP up)) (NP (DT an) (JJ electromagnetic) (NN wave)))))) (VP (VBP are) (PP (IN at) (NP (NP (JJ right) (NNS angles)) (PP (PP (TO to) (NP (DT each) (JJ other))) (CC and) (PP (TO to) (NP (DT the) (NN direction)))))) (SBAR (IN that) (S (NP (DT the) (NN wave)) (VP (VBZ travels))))))) (, ,) (NP (DT an) (JJ electromagnetic) (NN wave)) (VP (VBZ is) (VP (VBN considered) (S (NP (DT a) (-LRB- -LRB-) (NN n) (-RRB- -RRB-) (NN transverse) (NN wave))))) (. .)))