Generally speaking, previewing at ordinary times, listening to lectures carefully, finishing several homework carefully, and doing the real questions in previous years before the exam are enough for you to get good grades. The time to brush the questions is not fragrant when you participate in various competitions in the community and learn your own fields of interest. The purpose of brushing questions in high school is to improve proficiency and grades, while the learning difficulty and depth in universities are much more than those in high school. Brushing the questions is not the purpose, because what the university wants is not your proficiency in doing the questions, but.