(IP (NP-SBJ (-NONE- *pro*))
(VP (ADVP (AD 都))
(VP (VC 是)
(PP-PRD (P 因为)
(IP (IP (NP-SBJ (NN 农村))
(VP (VV 贫无立锥)))
(PU ，)
(IP (NP-SBJ (NN 农民))
(VP (ADVP (AD 不得不))
(VP (VP (VV 寄居)
(PP (P 在)
(NP (NP (CP (WHNP-1 (-NONE- *OP*))
(CP (IP (NP-SBJ (-NONE- *T*-1))
(VP (VA 富裕)))
(DEC 的)))
(NP (NN 都市)))
(NP (NN 底层)))))
(VP (VV 讨生活))))))))))
ARG0: 农村
REL: 贫无立锥