(IP 
  (PP-LOC 
    (P 在)
                    
    (NP 
      (NN 染色)
                    
      (NN 阶段)))
                    
  (ADVP 
    (AD 又))
                    
  (NP-SBJ 
    (ADVP 
      (AD 只有))
                    
    (NP 
      (CP 
        (WHNP-1 
          (-NONE- *OP*))
                    
        (CP 
          (IP 
            (NP-SBJ 
              (-NONE- *T*-1))
                    
            (VP 
              (ADVP 
                (AD 极))
                    
              (VP 
                (VA 小))))
                    
          (DEC 的)))
                    
      (NP 
        (NN 染料)
                    
        (NN 分子))))
                    
  (VP 
    (ADVP 
      (AD 才))
                    
    (VP 
      (VPT 
        (VV 渗)
                    
        (DER 得)
                    
        (VV 进去)))))
arg0: 
                    只有 *OP* *T*-1 极 小 的 染料 分子 
                
argm: 
                    才 
                
argm: 
                    又 
                
argm: 
                    在 染色 阶段