First of all, you can make up lessons. If you don't learn well, you can make up for it. There are many places to make up for it now. If it really doesn't work, you can hire a tutor (students in normal colleges are better). Otherwise, you can make it up with your classmates in Grade One and Grade Two. Don't be afraid of shame. You can also buy information books for the students in Grade One and Grade Two, and find some review materials from the Internet (forget the XX skills of college entrance examination where QQ space is full). As for the math class ... listen if you can, and do the questions in this section yourself if you don't understand ... above.