which may be why it works as well as it does 
(ROOT (SBAR (WHNP (WDT which)) (S (VP (MD may) (VP (VB be) (SBAR (WHADVP (WRB why)) (S (NP (PRP it)) (VP (VBZ works) (ADVP (ADVP (RB as) (RB well)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBZ does)))))))))))))
(ROOT (SBAR (WHNP (WDT )) (S (VP (MD ) (VP (VB ) (SBAR (WHADVP (WRB )) (S (NP (PRP )) (VP (VBZ ) (ADVP (ADVP (RB ) (RB )) (SBAR (IN ) (S (NP (PRP )) (VP (VBZ )))))))))))))