Language: a complete interpretation of mathematics in teaching materials: notes for top scholars, foreign languages: reading editions. If it is a benevolent version, it is best to buy the original textbook to explain. Other versions, such as materialization, biology, geography and political history, need to buy top notes. The above is just my personal opinion. In fact, what counseling books to buy, it is best to choose from a bigger bookstore, read more books and find the one that suits you best, because the one that suits you is the best.