It is not difficult to choose and fill in the blanks. The first question is the basis of the big topic, the second question is to see the topic clearly (not put it back), and the third question series can be done by induction, which is simpler than the 13 and 14 series. The fourth problem is to be careful not to miscalculate. The fifth problem is to use coordinates to represent points and find the equation of equal relationship. The last question should be good at classified discussion, and it will be helpful to take absolute inequality as an elective course.