17. (   ) ! The subway is approaching. 

• A、Look out
  
  

• B、Look back
  
  

• C、Look up
  
  

• D、Look down
  
  

8. My uncle has two daughters, and (   ) are doctors. 

• A、all of them
  
  

• B、both of them
  
  

• C、neither of them
  
  

• D、two of them
  
  

55. (     )