It's huge. According to the introduction of the champion, it is very difficult for the champion to win the championship. Basic knowledge is relatively solid. If you want to improve and expand, you can still choose this teaching aid. Algebraic expression (Grade 7)/Top students won the championship, edited by Liu Mao and Lv Chunxin, in order to further improve their learning level and impact Olympic medals. Top students win the championship with comprehensive questions, detailed answers, reasonable arrangement and difficulty from shallow to deep, which is a good helper in learning mathematics.