1. Physics is a natural science, which requires students to master physical laws, physical formulas and the ability to solve physical problems. The difficulty of physics is mainly reflected in the understanding and application of physical concepts and formulas, and students also need to have a certain mathematical foundation. Physics subjects are usually flexible, which requires students to have innovative thinking and problem-solving ability.

2. History is a social science, which requires students to master the knowledge of historical events, historical figures and historical periods. The difficulty of history is mainly reflected in the memory and understanding of historical events, and students also need to have certain ability of analysis and judgment. History is usually a complex subject, which requires students' patience and meticulous attitude.