( Sunspots ( ( ( ( come and ) go ) ( over ( an ( 11-year cycle ) ) ) ) . ) )
(ROOT (S (NP (NNS Sunspots)) (VP (VBP come) (CC and) (VBP go) (PP (IN over) (NP (DT an) (JJ 11-year) (NN cycle)))) (. .)))
Sunspots come and go over an 11-year cycle.
(ROOT (S (NP (NNS Sunspots)) (VP (VBP occur) (PP (IN in) (NP (DT a) (CD 11) (NN year) (NN cycle)))) (. .)))