Đáp án tham khảo có thể sai: 1a, 2a, 3b, 4ab, 5b, 6a, 7a, 8ad, 9b, 10b, 11a, 12a, 13a, 14b, 15a, 16a, 17d, 18d, 19a, 20a, 21a, 22a, 23a, 24c, 25a, 26a, 27c, 28d, 29c, 30a, 31a, 32d, 33a, 34a, 35c, 36b, 37a, 38b, 39a, 40b, 41c, 42a, 43e, 44b, 45a, 47b, 48d, 49c, 50b. Source: DBI202 - FE - SU 2023