( ( ( The levels ) ( of ( the ( female ( hormone estrogen ) ) ) ) ) ( ( change ( with ( the ( menstrual cycle ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS levels)) (PP (IN of) (NP (DT the) (JJ female) (NN hormone) (NN estrogen)))) (VP (VBP change) (PP (IN with) (NP (DT the) (JJ menstrual) (NN cycle)))) (. .)))
The levels of the female hormone estrogen change with the menstrual cycle.
(ROOT (S (NP (JJ Menstrual) (NN cycle)) (VP (VBZ is) (NP (NP (DT the) (NN name)) (PP (IN for) (NP (NP (DT a) (NN series)) (PP (IN of) (NP (NP (NNS changes)) (PP (IN in) (NP (NP (DT the) (JJ reproductive) (NN system)) (PP (IN of) (NP (JJ mature) (NNS females))))))))) (SBAR (WHNP (WDT that)) (S (VP (VBZ repeats) (NP (NP (DT every) (NN month)) (PP (IN on) (NP (NN average))))))))) (. .)))