Elective textbooks generally begin to study in the second year of high school. Elective course is a term in the reform of new curriculum standard and a course type in the adjustment of curriculum structure. Contrary to elective courses, it is a compulsory course and an elective course. The textbooks of elective courses in ordinary high schools are not compiled by the Ministry of Education, nor are they audited by the Ministry of Education. They are all independently compiled by publishing houses or schools, and students learn independently. Elective courses are generally relatively simple and rare, so we should choose them according to our actual situation.