(IP 
  (NP-SBJ 
    (ADJP 
      (JJ 大))
                    
    (NP 
      (NN 峡谷)))
                    
  (VP 
    (PP 
      (P 比)
                    
      (NP 
        (CP 
          (WHNP-2 
            (-NONE- *OP*))
                    
          (CP 
            (IP 
              (NP-SBJ 
                (NN 人们))
                    
              (VP 
                (ADVP 
                  (AD 原先))
                    
                (VP 
                  (VV 认为)
                    
                  (NP-OBJ 
                    (-NONE- *T*-2)))))
                    
            (DEC 的)))))
                    
    (ADVP 
      (AD 更))
                    
    (VP 
      (VA 狭窄))))
arg0: 
                    大 峡谷 
                
argm: 
                    更 
                
argm: 
                    比 *OP* 人们 原先 认为 *T*-2 的