- Interchange Third Edition is a 4-level series for adult and young adult learners of English from the beginning to the high-intermediate level. The Student"s Book B, Intro, is part of the introductory level of the Interchange Third Edition series. Intro is designed for beginning students needing a thorough, slow-paced presentation of basic functions, grammar structures, and vocabulary. Intro is based on the principle that low-level learning does not equal low-level thinking. Student"s Book B contains units 9-16, the second half of the full Student"s Book, along with frequent Progress Checks that allow students to assess and monitor their own learning, and a self-study section. Included is a Student Audio CD that contains the Snapshots, Word Powers, Conversations, Pronunciation, and self-study section from the Student"s Book. As with the other levels of Interchange Third Edition, a complete set of ancillaries is available to make classes productive, varied, and fun.