Interchange Fourth Edition is a four-level series for adult and young-adult learners of English from the beginning to the high-intermediate level. Student's Book B, Level 1 builds on the foundations established in the Intro level for accurate and fluent communication, extending grammatical, lexical, and functional skills. Student's Book B, Level 1 contains units 9-16, the second half of the full Student's Book, progress checks, additional Interchange activities, and a Grammar Plus section that provides additional grammar explanations and practice. Included is a Self-study DVD-ROM that provides the full class video and extra practice with vocabulary, grammar, speaking, listening, and reading.