What is the possessive form of cover and book?

Here are the possessive forms of "cover" and "book":

* Cover: The possessive form of "cover" is cover's. For example, "The book's cover was torn."

* Book: The possessive form of "book" is book's. For example, "I enjoyed the book's ending."

You can also use the phrase "of the" instead of the possessive form:

* "The cover of the book was torn."

* "I enjoyed the ending of the book."