that 's as entertaining as it is instructive 
(ROOT (S (NP (DT that)) (VP (VBZ 's) (ADJP (ADJP (RB as) (JJ entertaining)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBZ is) (ADJP (JJ instructive)))))))))
(ROOT (S (NP (DT )) (VP (VBZ ) (ADJP (ADJP (RB ) (JJ )) (SBAR (IN ) (S (NP (PRP )) (VP (VBZ ) (ADJP (JJ )))))))))