But what about a reference by MacNeil's partner, Jim Lehrer, to  some ten thousand black gold and diamond miners [on strike in South Africa]. 
( But ( what ( ( ( ( ( about ( a reference ) ) ( by ( ( ( ( ( MacNeil 's ) partner ) , ) ( Jim Lehrer ) ) , ) ) ) ( to ( ( some ( ten thousand ) ) ( black ( gold ( and ( diamond miners ) ) ) ) ) ) ) ( ( -LSB- ( on strike ) ) ( in ( South ( Africa -RSB- ) ) ) ) ) . ) ) )
(ROOT (S (CC But) (NP (WDT what)) (VP (ADVP (IN about) (NP (DT a) (NN reference)) (PP (IN by) (NP (NP (NP (NNP MacNeil) (POS 's)) (NN partner)) (, ,) (NP (NNP Jim) (NNP Lehrer)) (, ,))) (PP (TO to) (NP (QP (DT some) (CD ten) (CD thousand)) (JJ black) (NN gold) (CC and) (NN diamond) (NNS miners)))) (VBD -LSB-) (PP (IN on) (NP (NN strike))) (PP (IN in) (NP (NNP South) (NNP Africa) (NNP -RSB-)))) (. .)))
MacNeil worked alone.
( MacNeil ( ( worked alone ) . ) )
(ROOT (S (NP (NNP MacNeil)) (VP (VBD worked) (ADVP (RB alone))) (. .)))