A) Fill in prepositions of time At/in/on as in the example : 

 1. ___on___ Saturday

 2. ______ July 

 3. ______ 1984

 4. ______ March 25th 

 5. ______ Friday

 6. ________ summer

 7. _______ the morning

 8. _______ 9 o'clock 

 9. ______ Christmas

10. _____ September 28th

11. _____ 199 

12. _____ August 29th

13. ______ winter

14. ______ the evening

15. _______ Autumn 

16. ______ half past two

17. ______ Monday morning

18. ______ Easter

Bài 1 : Tính nhanh 

  a, 2/3 + 2/6 + 2/12 + 2/24 + 2/48 + 2/96 + 2/192