Number of testimonies
( Number ( of testimonies ) )
(ROOT (NP (NP (NNP Number)) (PP (IN of) (NP (NNS testimonies)))))
They are all from constituents.
( They ( ( ( are all ) ( from constituents ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP are) (RB all) (PP (IN from) (NP (NNS constituents)))) (. .)))