Students attend classes after previewing, and the enthusiasm and purpose of attending classes are often stronger than those without previewing. We know that, in fact, the time for preview is always limited, plus the limitation of personal ability. Therefore, it is impossible to master all the textbooks in preview, and there will always be some problems we don't understand, which we hope to solve in class. In this way, the enthusiasm and purpose of class will naturally be stronger.

Through preview, we have a preliminary understanding of knowledge, and after the teacher's explanation, guidance and inspiration in class, our understanding of knowledge can enter a higher level. Specifically, when the teacher talks about the part that has been preliminarily understood in the preview, he can learn from the teacher's ideas in the lecture and compare them with his own ideas in the preview to see how the teacher asks questions, analyzes and solves them, where the teacher's ideas are better than his own and why. Of course, it is essential to verify whether his understanding of knowledge is correct. After such a comparison, we can learn from each other's strong points, not only make our knowledge more solid, but also improve our awareness of learning. So, on the surface, students sit in the classroom and listen quietly, but in fact, everyone's starting point and acceptance ability are different. Students who have no preview will find it difficult to understand in class if they have a poor foundation, so they have no energy to consider deeper problems at all.

2. Preview can change the passive situation of learning.

Because preview can remove knowledge obstacles in classroom learning, improve listening and speaking level, strengthen the pertinence of classroom notes and greatly enhance the effect of class, the classroom learning situation as a learning center has changed, thus changing the passive situation of learning and reducing the classroom learning time wasted because of incomprehension; I get it in class, and the time for reviewing and doing homework after class is also greatly saved. Of course, it takes some time to preview, but it is insignificant compared with classroom listening, after-class review and homework strengthening.

3. Preview can improve self-study ability.

There is a great difference between studying in university and studying in middle school. The main features are: large amount of knowledge, great difficulty, strong theory, fast lecture progress, many notes (because there are no books in some subjects), reduced proportion of classroom teaching, increased self-study time, wonderful lectures by teachers, and students need to learn more by themselves. After a class, sometimes I have to read dozens of pages of textbooks and learn by myself; The teacher's management of students is reduced, and the time is mainly arranged and mastered by the students themselves, which greatly strengthens the initiative and independence of students' learning. All these require college students to have strong self-study ability.