NORAD officials have maintained that they would have intercepted and shot down United 93.
( ( NORAD officials ) ( ( have ( maintained ( that ( they ( would ( have ( ( ( intercepted and ) shot ) ( down ( United 93 ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP NORAD) (NNS officials)) (VP (VBP have) (VP (VBN maintained) (SBAR (IN that) (S (NP (PRP they)) (VP (MD would) (VP (VB have) (VP (VBN intercepted) (CC and) (VBN shot) (PP (IN down) (NP (NNP United) (CD 93)))))))))) (. .)))
NORAD officials still say they would have shot down United 93.
( ( NORAD officials ) ( still ( ( say ( they ( would ( have ( shot ( down ( United 93 ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (NNP NORAD) (NNS officials)) (ADVP (RB still)) (VP (VBP say) (SBAR (S (NP (PRP they)) (VP (MD would) (VP (VB have) (VP (VBN shot) (PP (IN down) (NP (NNP United) (CD 93))))))))) (. .)))