The purpose of the exam is to distinguish the level of candidates. Therefore, the test paper that can achieve this goal is considered a "good test paper". If all the questions on a test paper are simple enough for all staff to complete easily, it is impossible to distinguish the level of candidates; On the other hand, if the test paper is too difficult for everyone to do, it is obviously impossible to know which candidate has a high level. A "good" test paper should make some high-level candidates get high marks and low-level candidates get low marks, so as to distinguish them-this is the purpose of the college entrance examination.