What students learn in class, that is, what teachers say in class, is generally to compare the basic knowledge points first.

The teacher may talk more about a series of topics, technical problem-solving methods and ideas. The topics may be classic and representative, and the original questions will not be tested in the exam.

The topic of the exam does not mean that it is completely divorced from what is said in class. The knowledge points of exam questions, such as some problem-solving steps, are completely similar to those in class, but they can't be exactly the same. There are many new topics every year, which is the reason.