( 
  (IP 
    (ADVP 
      (AD 然而))
                    
    (NP-SBJ 
      (NN 平静))
                    
    (VP 
      (ADVP 
        (AD 只))
                    
      (VP 
        (VC 是)
                    
        (NP-PRD 
          (CP 
            (WHNP-1 
              (-NONE- *OP*))
                    
            (CP 
              (IP 
                (NP-SBJ 
                  (-NONE- *T*-1))
                    
                (VP 
                  (VA 表面)))
                    
              (DEC 的))))))))
arg0:  *T*-1