hard to imagine acting that could be any flatter 
(ROOT (ADJP (JJ hard) (S (VP (TO to) (VP (VB imagine) (S (VP (VBG acting) (SBAR (WHNP (DT that)) (S (VP (MD could) (VP (VB be) (ADJP (DT any) (JJR flatter)))))))))))))
(ROOT (ADJP (JJ ) (S (VP (TO ) (VP (VB ) (S (VP (VBG ) (SBAR (WHNP (DT )) (S (VP (MD ) (VP (VB ) (ADJP (DT ) (JJR )))))))))))))