2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20A X XB X X XC X...

Câu

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

A

X

X

B

X

X

X

C

X

X

X

X

X

D

X

X

X

X