(CP 
  (WHNP-1 
    (-NONE- *OP*))
                    
  (CP 
    (IP 
      (NP-SBJ 
        (-NONE- *T*-1))
                    
      (VP 
        (VP 
          (NP-PRD 
            (QP 
              (OD ２))
                    
            (NP 
              (NN 级))))
                    
        (CC 和)
                    
        (VP 
          (VV 好于)
                    
          (NP-OBJ 
            (QP 
              (OD ２))
                    
            (NP 
              (NN 级))))))
                    
    (DEC 的)))
                    
(NP 
  (NN 天数)))
arg0: 
                    *T*-1 -> 天数          
                
arg1: 
                    ２ 级