every possible angle has been exhausted by documentarians 
(ROOT (S (NP (DT every) (JJ possible) (NN angle)) (VP (VBZ has) (VP (VBN been) (VP (VBN exhausted) (PP (IN by) (NP (NNS documentarians))))))))
(ROOT (S (NP (DT ) (JJ ) (NN )) (VP (VBZ ) (VP (VBN ) (VP (VBN ) (PP (IN ) (NP (NNS ))))))))