1. Why? Sports Science (Why? Sports Science English Edition) Why? The Human Body, created together by a team of Harvard graduates This book stands out thanks to the meticulous supervision of Ms. Mok Jin-sil, a former U.S. elementary science teacher, and the careful editing of Harvard-educated editors Scott Lichtenstein and David Vincent Kimmel. Why? English Edition and Korean Edition — read them together! The Why? English Edition is a direct 1:1 translation of the Korean edition, allowing children to study both versions side by side for effective repeated learning. Through this repetition, kids can naturally absorb not only everyday conversational expressions but also challenging scientific terminology. 2. Science Workbook A proven workbook co-developed with McGraw-Hill, the renowned U.S. textbook publisher! This workbook was jointly developed with McGraw-Hill, famous for publishing textbooks used across the United States. It combines Yearimdang's content with McGraw-Hill's expertise in developing English learning materials. Self-Checking Through a Variety of Question Types! With various question types (Vocabulary, Reading Comprehension, Summary, Speaking, Puzzle), children can check how well they've understood the content of the Why? English Edition. The workbook also helps kids learn essential vocabulary at a U.S. elementary school level, and the answer key with explanations makes it easy to understand the meaning of each example sentence. 3. Vocabulary List A pocket-sized vocabulary list containing all the essential words every elementary student should know! This list features key vocabulary selected from each chapter of the Why? English Edition, along with definitions and example sentences. The words are organized according to the flow of the story, so children can reconstruct the content just from the vocabulary alone. Its compact size also makes it easy to carry around. 4. Audio CD The entire Why? English Edition on 3 audio CDs! Listen to the dialogue of the Why? English Edition characters performed vividly by native English speakers. With these audio CDs alone, children can hear the entire content of the Why? English Edition, learning accurate native pronunciation while improving both listening and speaking skills.