上课集中精神。 作笔记。 当你不理解的时候要主动提问。 检查课表。 白天吃点点心。 找到一种有效的学习方式。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
The best thing you can do to improve your grades is focus and pay attention when the information is first presented to you. It's easy to lose focus when your teacher is going on and on about something that's  not interesting, but you should not tune them out. Really listen to what they're saying and keep yourself engaged by asking questions and taking notes. . It might seem silly, but notes are actually a great way to help you improve your grades. Good notes are like a road map, when you go to s