that might otherwise separate them 
(ROOT (SBAR (WHNP (DT that)) (S (VP (MD might) (ADVP (RB otherwise)) (VP (VB separate) (NP (PRP them)))))))
(ROOT (SBAR (WHNP (DT )) (S (VP (MD ) (ADVP (RB )) (VP (VB ) (NP (PRP )))))))