( Again ( this ( ( ends ( in ( ( a ( repeating cycle ) ) ( of ( period 15 ) ) ) ) ) . ) ) )
(ROOT (S (ADVP (RB Again)) (NP (DT this)) (VP (VBZ ends) (PP (IN in) (NP (NP (DT a) (JJ repeating) (NN cycle)) (PP (IN of) (NP (NN period) (CD 15)))))) (. .)))
Again this ends in a repeating cycle of period 15.
(ROOT (S (NP (DT The) (NN water) (NN cycle)) (VP (VBZ ends) (SBAR (IN with) (S (NP (PRP it)) (VP (VBZ repeats) (NP (PRP itself)))))) (. .)))
The water cycle ends with it repeats itself.