It's good to return something you've borrowed.
Suzy is looking for something to do on a rainy day to have some fun.
Suzy wants to get some books from the library.
Suzy reads the books and when she is done with them she takes them to the library and returns them.
Suzy reads the books and puts them in her closet forgetting about them afterward.
Other people get a chance to read the books when they want to and enjoy themselves.
Suzy get's a letter in the mail telling her about a huge fine she has and to return the books.