's not clear whether we 're supposed to shriek 
(ROOT (VP (VBZ 's) (RB not) (ADJP (JJ clear)) (SBAR (IN whether) (S (NP (PRP we)) (VP (VBP 're) (VP (VBN supposed) (S (VP (TO to) (VP (VB shriek))))))))))
(ROOT (VP (VBZ ) (RB ) (ADJP (JJ )) (SBAR (IN ) (S (NP (PRP )) (VP (VBP ) (VP (VBN ) (S (VP (TO ) (VP (VB ))))))))))