what can easily be considered career-best performances 
(ROOT (SBAR (WHNP (WP what)) (S (VP (MD can) (ADVP (RB easily)) (VP (VB be) (VP (VBN considered) (S (NP (NML (NN career) (HYPH -) (JJS best)) (NNS performances)))))))))
(ROOT (SBAR (WHNP (WP )) (S (VP (MD ) (ADVP (RB )) (VP (VB ) (VP (VBN ) (S (NP (NML (NN ) (HYPH ) (JJS )) (NNS )))))))))