They were simply told, "These are the 'A-students,' these are the 'D-students.'" And that's how they went about teaching them and treating them.
누구는 우등생, 누구는 열등생이란 말만 들은 것이에요. 선생님들은 들은대로 학생들을 대하고 가르쳤던 거죠.