19. I'll do (   ) the guide said.

• A、as
  
  

• B、as if
  
  

• C、that
  
  

• D、all which
  
  

8. (   ) is well-known, the earth moves around the sun. 

• A、Which
  
  

• B、What
  
  

• C、As
  
  

• D、It
  
  

55. (    )