Because these three subjects are the most widely used. Regardless of occupation or knowledge, everyone can't do without these three courses, especially Chinese and mathematics.

Chinese is the foundation of culture, and it is used in daily communication, expressing ideas, writing papers and so on. Chinese is also the basis for learning other sciences.

Mathematics is very important and indispensable in life, production and scientific research. The more advanced science is, the higher the requirements for mathematics will be.

The importance of English lies in understanding the world and going to the world. Let the world know about China and let China go to the world. We should use English. English is the first choice among all foreign languages.