( ( What ( worked ( for ( one landing ) ) ) ) ( ( ( might not ) ( work ( for another ) ) ) . ) )
(ROOT (S (SBAR (WHNP (WP What)) (S (VP (VBD worked) (PP (IN for) (NP (CD one) (NN landing)))))) (VP (MD might) (RB not) (VP (VB work) (PP (IN for) (NP (DT another))))) (. .)))
What worked for one landing might not work for another.
(ROOT (S (S (VP (TO To) (VP (VB confirm) (NP (NP (DT the) (NN work)) (PP (IN of) (NP (DT another) (NN scientist))))))) (, ,) (NP (DT a) (NN scientist)) (VP (MD might) (VP (VB replicate) (NP (PRP$ their) (NN work)))) (. .)))