Interchange Third edition is a four-level series for adult and young-adult learners of English from the beginning to the high-intermediate level. The Interchange Third Edition Workbook has six-page units that follow the same sequence as the Student"s Book, recycling and reviewing language from previous units. It provides additional practice in grammar, vocabulary, reading, and writing. The Workbook can be appropriate for in-class work or assigned as homework. Workbook B contains units 9-16, the second half of the Level 1 Workbook.