Smartphones and e-readers have become more common in recent years.However , paper books still have a key role 1 . (play) . In the UK , the sales of e-books are falling 2 . those of traditional books are rising.More surprisingly , it’s young people who are buying paper books. What is behind the comeback of the paper book ? First , readers like to hold the product.It’s true that paper books offer 3 . unique reading experience.Japanese students even said that they like the smell of paper books.Other students said that they get a sense of 4 . (achieve) when they finish reading a paper book and they enjoy seeing it 5. the bookshelf. Besides , paper books can also be personal objects to lovers of reading , many of 6 . like to sign their names on the inside cover.If the cover gets bent or there’s a stain( 污点 ) 7 . (make) on the pages from coffee or food , all the better.Such 8 . (incident) make the book more like a personal friend to them. Amazing as it seems , research has shown readers remember more information when reading from paper books than e-books.Meanwhile , people are more likely to have 9 . (pain) eyes or headaches after reading e-books long. Therefore paper books , which 10 . (be) in production since the 15th century , still have an attraction.