2. Elementary mathematics, content: set, algebraic expression formula and root, equation and inequality, basic elementary function, complex number, permutation and combination and probability theory, determinant, linear equations and matrix, analytic geometry.
3. English, content: text, new words, phrases and expressions, main explanation, exercises, etc.
4. Preparatory classes originated in universities and colleges in western countries in the second half of the 18th century, which refers to a special level of higher education. It belongs to pre-university preparatory education, and generally requires senior three graduates to study for about one year in order to adapt to the learning style of universities.
5. Before liberation, some schools in China set up a one-year preparatory course, which was gradually cancelled. After the founding of New China, the Institute for Nationalities has set up some preparatory classes for ethnic minorities, and a considerable number of preparatory classes for ethnic minorities have also been held in other colleges, secondary specialized schools and adult colleges. In 1996, there were more than 14 institutions of higher learning holding ethnic preparatory courses in China, with 11,622 students.
6. Preparatory education has played a great role in improving the basic cultural knowledge of ethnic minority students and enabling more ethnic minority students to enter higher and secondary specialized schools. It has become a unique form of running schools mainly for ethnic minority students and an important part of ethnic education.