One Sunday afternoon, I went to a bookshop to buy some books. When I arrived at the bookshop, there were not many people. I went around the bookshelves to look for the book I wanted to buy. At that time, I noticed a girl behind me. Whenever I stopped at a bookshelf, she also stopped behind me. I thought that she was a pickpocket. At first, I did not know what to do. Then, I got an idea and turned round to look straight at her. Suddenly, she said, "Your skirt was torn at the back. I'm trying to cover that tear not to be seen by others."