Đáp án tham khảo: 1C, 2B, 3D, 4A, 5DE, 6D, 7C, 8C, 9A, 10D, 11A, 12AC, 13A, 14B, 15A, 16A, 17C, 18AC, 19A, 20C, 21D, 22D, 23C, 24B, 25CE, 26B, 27C, 28B, 29B, 30D, 31D, 32A, 33CD, 34A, 35A, 36C, 37D, 38B, 39C, 40A, 41A, 42D, 43C, 44A, 45A, 46D, 47A, 48D, 49D, 50BD,