In fact, microelectronics is the most promising of the four things you study physics, followed by electronic information science and technology. In the field of physics and astronomy, if you want to make a big breakthrough, you must spend a very long time here. Sometimes even a doctor with a higher level will not have a good economic income. Because there is too little contact with reality. Microelectronics and electronic information science and technology are related to electronic equipment, which will be a huge space in the future. If a better microelectronics engineer earns a good income, it will be considerable. In fact, the department of mathematics is more useful than the department of physics. Because many large financial statistics institutions like to accept graduates from mathematics departments, because stock analysis, forecasting or statistical co-ordination are inseparable from mathematics. If you really like traditional physics and astronomy, if your family conditions are very good, you can consider studying until you can stay as a professor ... or you can work in the national aerospace department ... of course, the road ahead looks even more illusory.