( The ( 11-year ( sunspot ( cycle . ) ) ) )
(ROOT (NP (DT The) (JJ 11-year) (NN sunspot) (NN cycle) (. .)))
The 11-year sunspot cycle.
(ROOT (S (NP (NNS Sunspots)) (VP (VBP occur) (PP (IN in) (NP (DT a) (CD 11) (NN year) (NN cycle)))) (. .)))