The third option is to add to what is in the book. If the lesson is rather boring, too controlled, or if it gives no chance for students to use what they are learning in a personal kind of way, the teacher may want to add activities and exercises which extend the students’ engagement with the language or topic
Addition is a good alternative since it uses the textbook’s strengths but marries them with the teacher’s own skills and perceptions of the class in front of him or her.