The boomerang series is designed as an in-class teaching tool. it consists of a topic summary in a piece-to-whole logic, in-class activity, in-depth tests, cumulative boomerang tests and skill tests. more than 100 stocks are available to be sold at the campaign price. the listed price is valid until october 16, 2026. Improved version for clearer understanding and better search visibility. Suitable for users seeking detailed and reliable product information.