13 session is difficult. The National College Students' Mathematics Competition is the largest and highest-level college students' mathematics competition organized by the Chinese Mathematical Society. The national unified proposition is published, and the test paper is very difficult. 13 test questions are not difficult to fill in the blanks, which is within the difficulty range of postgraduate mathematics, but the difficulty of big questions is still relatively large. Except for the big question 1, other big questions are much more difficult than the postgraduate entrance examination. 18. China Mathematics Competition (CMC) is a national high-level academic competition for college students sponsored by the Chinese Mathematical Society. It is also a good relay of the national high school mathematics competition in colleges and universities. Participants are sophomores or above. The competition is divided into non-mathematical professional groups and mathematical professional groups (including students majoring in mathematics and applied mathematics, information and computing science), and students majoring in mathematics are not allowed to participate in the competition of non-mathematical professional groups.