English graded readers: LADDER SERIES and HOLES. A study guide featuring explanations of Leonardo da Vinci and Zuckerberg, along with HOLES. A set of 3 books. Perfect for extensive reading. Extensive reading is also effective for listening comprehension, and I used these books for that purpose. The Ladder Series is ideal for extensive English reading, with a wide range of easy-to-read content from classic literature to biographies and fairy tales. There are no markings, but please understand that these are used items before purchasing. Thank you for looking.