The books are graded at six vocabulary levels, ranging from 250 key words (Beginning) to 2,500 key words (Advanced.) OXFORD BOOKWORMS LIBRARY New Edition STAGE 4 BESTSELLER PACK (1,400 key words) contains one copy each of the following ten titles: Black Beauty Dr Jekyll and Mr Hyde Gulliver´s Travels The Hound of the Baskervilles Little Women Silas Marner A Tale of two Cities The Thirty-Nine Steps Three Men in a Boat Treasure Island