Reading is fun.When you read,would you like a paper book or an e-book(电子书)? Some people choose e-books,some love paper books,and others like reading both. Li Ming,a university professor(教授),is busy doing some research.So he is often on business.When he is at the airport or on the train, he usually loves reading e-books. He also likes reading paper books in the library for his research work.Besides,he enjoys the smell of the paper books. What's more, Li Ming would like to read with his family. There is a reading time from 8:00 to 9:00 each Friday evening at home.Everyone reads and shares what they learn from the books.One Friday evening,Grandma took out an old paper book and said to her grandson,"Li Ming,this is the first book your grandpa gave me.There is his name on the front page.Whenever I read it,I can get something new from his notes.And I can still remember the happy lite we lived together."Li Ming said,"But I enjoy reading e-books. E-books need no paper.Many forests will be saved." Grandma advised,"Don't read for a long time,or your eyes will get sore." Different people have different ideas about e-books and paper books.No one knows whether e-books can replace(代替) paper books or not.Somehow,books are our friends.No matter which kind of books you choose to read,you can learn more about the world through them. 根据短文内容,回答下列问题。 3.What does the old paper book mean to Grandma? _______________________________________________