, they 'll probably run out screaming . 
(ROOT (S (, ,) (NP (PRP they)) (VP (MD 'll) (ADVP (RB probably)) (VP (VB run) (PRT (RP out)) (S (VP (VBG screaming))))) (. .)))
(ROOT (S (, ) (NP (PRP )) (VP (MD ) (ADVP (RB )) (VP (VB ) (PRT (RP )) (S (VP (VBG ))))) (. )))