Đáp án tham khảo có thể sai: 1b, 2d, 3d, 4b, 5b, 6a, 7a, 8d, 9b, 10e, 11b, 12b, 13e, 14b, 15e, 16a, 17b, 18b, 19e, 20c, 21c, 22e, 23d, 24a, 25d, 26b, 27c, 28e, 29e, 30b, 31a, 32b, 33b, 34d, 35c, 36d, 37a, 38c, 39a, 40a, 41e, 42b, 43e, 44d, 45a, 46b, 47e, 48a, 49d, source : ECO201_FA23_FE_922515