44. You shouldn't sit with your back towards the window because (   ). 

• A、the light is too bright
  
  

• B、the light is bad for your eyes
  
  

• C、you are in a dark room
  
  

• D、your book is in your shadow
  
  

52 .(    ).

33. (      )

• A、writes
  
  

• B、was writing
  
  

• C、has written
  
  

• D、had written