l am terribly sorry to tell you that l have lost the valuable book you were so kind to lend me last week.The book was missing because of my carelessness.Yesterday l took the book with me to the park and read it there.But when l came back home ,it was nowhere to be found. l tried to look for it everywhere but in vain. So l bought a new one for you. l know books are like friends. Once lost,they can never be replaced.l am afraid zhe new book can never take the place of the old one .And about this irrecoverable loss, l feel really guilty. l have always been careless with my things.this is a warning to me to be more careful in the future.