before each number. 1. I am sometimes hardbound or paper I protect the book from its damage. Who am I? 2. I show the titles of selections, lessons or topics of a book. Who am I? _3. I am known as the heart of a book. Without ne, the book would not be of any use. Who am I? 4. I list all the topics of the book and arranged em alphabetically and give the pages where you can nd these topics. Who am I? 5. I give the title of the book, the author, or uthors and the publishing company together with its ddress. Who am I?​