( ( ( A period ) ( -LRB- ( ( measured ( in seconds ) ) -RRB- ) ) ) ( ( is ( ( ( the time ) ( for ( one wave ) ) ) ( to ( pass ( a ( given point ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN period)) (PRN (-LRB- -LRB-) (VP (VBN measured) (PP (IN in) (NP (NNS seconds)))) (-RRB- -RRB-))) (VP (VBZ is) (NP (NP (DT the) (NN time)) (PP (IN for) (NP (CD one) (NN wave))) (S (VP (TO to) (VP (VB pass) (NP (DT a) (VBN given) (NN point))))))) (. .)))
A period (measured in seconds) is the time for one wave to pass a given point.
(ROOT (S (NP (NN Period)) (VP (VBZ is) (NP (NP (DT the) (NN time) (NN interval)) (VP (VBN required) (PP (IN for) (NP (CD one) (JJ complete) (NN wave) (S (VP (TO to) (VP (VB pass) (NP (NP (DT a) (NN point)) (VP (VBN called))))))))))) (. .)))