After the graduation exam, the class leader wanted to inquire about the results of the teacher. The class leader said: "Teacher, this test is not difficult. It is estimated that the scores of our classmates are above 70. " Yes, the second sentence is wrong. ". According to the teacher, which of the following must be true? ['A few students have scores above 70, and most students have scores below 70.', 'Most students have scores above 70, and few students have scores below 70.', 'Some students have scores above 70, and some students have scores below 70.', 'If you pass the 70 marks, some students will definitely fail.']