Book excerpt: Interchange Fourth Edition is a four-level series for adult and young-adult learners of English from the beginning to the high-intermediate level. The Interchange Fourth Edition interleaved, spiral-bound Teacher's Edition with Assessment Audio CD/CD-ROM, Intro features complete teaching instructions, optional activities, audio scripts, language summaries, and Student's Book, Intro and Workbook, Intro answer keys. The Assessment CD/CD-ROM provides a complete assessment program, including oral a quizzes, as well as mid-term and final tests in printable PDF and Microsoft Word formats.