It is all-encompassing, integrating ancient and modern, covering the universe, the earth, nature, society, science, history, human beings, art and other aspects that make children feel most curious, showing a colorful world of knowledge in an all-round way, so that children can move forward easily and happily on the road of knowledge. This book can not only consolidate what children have learned in class, but also let them know about the unpredictable universe stories, colorful mysteries of the earth, complex and magical human structures, kingdoms of various things, interesting animal worlds, scientific principles of daily life and colorful human society every day after class.