(IP 
  (IP-SBJ 
    (NP-SBJ 
      (-NONE- *PRO*))
                    
    (VP 
      (VV 索讨)
                    
      (NP-OBJ 
        (CP 
          (WHNP-2 
            (-NONE- *OP*))
                    
          (CP 
            (IP 
              (NP-SBJ 
                (-NONE- *T*-2))
                    
              (VP 
                (NP-TMP 
                  (NN 早年))
                    
                (PP-PRP 
                  (P 因)
                    
                  (NP 
                    (NP 
                      (NN 政治)
                    
                      (PU 、)
                    
                      (NN 经济))
                    
                    (NP 
                      (NN 因素))))
                    
                (VP 
                  (VV 流失))))
                    
            (DEC 的)))
                    
        (NP 
          (NN 历史)
                    
          (NN 文物)))))
                    
  (PU ，)
                    
  (VP 
    (VC 是)
                    
    (NP-PRD 
      (NP 
        (NT 目前))
                    
      (DNP 
        (NP 
          (NN 世界)
                    
          (NN 博物馆界))
                    
        (DEG 的))
                    
      (ADJP 
        (JJ 热门))
                    
      (NP 
        (NN 议题)))))
arg0: 
                    *PRO* 
                
arg1: 
                    *OP* *T*-2 早年 因 政治 、 经济 因素 流失 的 历史 文物