This is very simple. The new curriculum reform in Beijing is completely a change of medicine, and compulsory courses must be learned. The so-called elective courses are basically empty shelves. The Beijing Municipal Education Commission has stipulated compulsory modules, which means that there is no difference between some elective courses and compulsory courses, and every school will definitely talk about them. The scope of the college entrance examination is compulsory modules and compulsory modules. After that, there are basically no other classes to take, and then you will know that the textbooks taught in each school are the same, and you don't even have a chance to read many textbooks that you don't have to choose, so don't worry about the different exam contents.
In addition, the school may offer one or two hours of elective courses. In elective courses, you can choose other modules, which has little to do with the college entrance examination. Just choose according to your own interests.