a natural sense for what works 
(ROOT (NP (NP (DT a) (JJ natural) (NN sense)) (PP (IN for) (SBAR (WHNP (WP what)) (S (VP (VBZ works)))))))
(ROOT (NP (NP (DT ) (JJ ) (NN )) (PP (IN ) (SBAR (WHNP (WP )) (S (VP (VBZ )))))))