Đáp án chỉ để tham khảo vẫn có thể sai: 1a, 2a, 3b, 4b, 5a, 6a, 7d, 8a, 9b, 10d, 11c, 12b, 13b, 14b, 15a, 16a, 17c, 18a, 19a, 20a, 21a, 22a, 23a, 24c, 25c, 26d, 27b, 28b, 29d, 30a, 31d, 32d, 33c, 34b, 35a, 36d, 37d, 38a, 39a, 40d, 41a, 42b, 43d, 44d, 45d, 46c, 47d, 48a, 49a, 50a. Source...