(NP-OBJ (CP (WHNP-2 (-NONE- *OP*))
(CP (IP (NP-SBJ (-NONE- *T*-2))
(VP (NP-TMP (NT 以往))
(ADVP (AD 曾))
(VP (VV 出现)
(AS 过))))
(DEC 的)))
(IP-APP (NP-SBJ (-NONE- *pro*))
(VP (VV 大起大落)))
(NP (NN 现象)))
ARG0: *pro*
REL: 大起大落