In this book, Lee, Pat and their friend Tom learn about all kinds of animals. They learn about animals we keep as pets. They learn about animals on farms, and they learn about animals that live in the wild. All the details in the book are revealed in language (words and structure) that has been rigorously selected to be as simple and understandable as possible for young readers.For example, did you know that just 25 most commonly used words make up about one-third of all words written or spoken in English? The first 100 most frequently used words make up about one-half of all written and spoken English. By the end of the 12-book Word by Word series, children will have learned the 1,000 most frequently used words which comprise more than 95% of all written and spoken English.The content of all Word by Word readers is based on extensive, diligent research into the most frequently used English words and structures. The key sight words and structures are presented gradually and systematically throughout the series. For example, all new words and structures are repeated at least 15 times subsequent to their first appearance in the series. This ensures effective and rapid learning as well as maximum retention and comprehension. It is this very systematic control of vocabulary and structure that makes Word by Word graded readers unique.All the books in the series have been extensively trialed and repeatedly improved over a period of many years and are now proven to be extremely effective in building functional literacy in children of many ages and nationalities, including the author's own children.