On the one hand, how can the source of this topic and its authoritative accuracy be unknown? On the other hand, watching the mobile phone for a long time is not good for your eyesight, so it is inevitable to draw a draft and write some conceptual formulas in the process of doing the problem. It is difficult to do this with a mobile phone or a tablet. If you use a paper book, you can write the answers and procedures in the book, which is also conducive to review and review in the future.
Summary of teaching and research work in the spring of 2023 1
This semester, all the teachers in