chap 4

1 chap 1 

2 chap 2 [h nhẹ] 

3 chap 3 

4 chap 4 

5 chap 5 

6 chap 6[h nhẹ] 

7 chap 7 

8 chap 8 

9 chap 9 

10 Chap 10[h+++] 

11 chap 11 

12 chap 12[h nhẹ] 

13 chap 13 

14 chap 14[h nhẹ] 

15 chap 15[h nhẹ] 

16 chap 16 

17 chap 17[h nhẹ] 

18 chap 18 

19 chap 19[h nhẹ] 

20 chap 20 

21 chap 21[h nhẹ] 

22 chap 22 