( ( This ( ten-year period ) ) ( ( was ( divided ( into ( three stages ) ) ) ) . ) )
(ROOT (S (NP (DT This) (JJ ten-year) (NN period)) (VP (VBD was) (VP (VBN divided) (PP (IN into) (NP (CD three) (NNS stages))))) (. .)))
This ten-year period was divided into three stages.
(ROOT (S (NP (NNP Adulthood)) (VP (VBZ is) (VP (VBN divided) (PP (IN into) (NP (CD three) (NNS stages))))) (. .)))