The learning materials in this book are presented systematically, communicatively, and integratively. At the beginning of each chapter, there is an opening picture of the lesson, aimed at providing an overview of the learning materials to be discussed, and teaching students the concept of contextual thinking while stimulating contextual thinking. In addition, this book is also arranged in an attractive format and supported by representative photos and illustrations. The use of simple language, in accordance with the cognitive level of students, makes it easier for readers to understand it.