Clinical medicine, mechanical design and manufacturing and automation, software engineering, materials science and engineering, mathematics and applied mathematics, electronic science and technology, electronic information engineering, electrical engineering and automation, energy and power engineering are all difficult majors for college students to learn.
But in fact, mathematics is 1 in our minds. Mathematics is arguably the most difficult subject in the world. Everyone has to go to college to rack their brains for mathematics, not to mention that the mathematics we are talking about is not high school mathematics, nor ordinary mathematics, but a collection of all mathematics. Everyone may have been troubled by mathematics.
There is also history, such as archaeological history, which is also very difficult for us to re-archaeology in high technology now.