A. did Mr Smith use to                      
B. did Mr Smith used to              
C. use Mr Smith to                          
D. Mr Smith used to

1. They are going to play computer games. (对划线部分提问)
   ______ are they going to ______?
2. Mr Smith came to China three years ago. (对划线部分提问)
   ______ did Mr Smith ______ to China?
3. You  shouldn't  turn on the blender. (改为祈使句)
   ______  ______ on the blender.
4. Pedro is 10 years old and Sam is 10 years old, too.  (改为同义句)
   ______ Pedro ______ Sam are 10 years old.
5. Lin Tao often goes to the movies on Sundays. (用next Sunday改写)
    Lin Tao ______  ______ to the movies next Sunday.