(IP (ADVP (AD 但))
(NP-SBJ (CP (WHNP-1 (-NONE- *OP*))
(CP (IP (NP-SBJ (-NONE- *T*-1))
(VP (VA 复杂)))
(DEC 的)))
(NP (NN 蛇)
(NN 毒) ))
(VP (ADVP (AD 不))
(VP (VA 易)
(IP-OBJ (NP-SBJ (-NONE- *PRO*))
(VP (VV 合成))))))
ARG1: *PRO*
REL: 合成