(IP (NP-SBJ (PN 这))
(VP (PP-LOC (P 在)
(LCP (NP (NP-PN (NR 联合国))
(NP (NN 历史)))
(LC 上)))
(VP (VC 是)
(NP-PRD (CP (WHNP-1 (-NONE- *OP*))
(CP (IP (NP-SBJ (-NONE- *T*-1))
(VP (VV 绝无仅有)))
(DEC 的)))))))
ARG0: *T*-1
REL: 绝无仅有