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 Level 1 Student's Book builds on the foundations established in the Intro for accurate and fluent communication, extending grammatical, lexical, and functional skills. Topics such as school, work, and food are presented in unique ways using interesting real-life information. The Student's Book contains 16 teaching units, frequent progress checks that allow students to assess and monitor their own learning, and a listening self-study section. Included is a Student Audio CD that contains the conversation, pronunciation, and self-study sections from the Student's Book. Student's Book B contains units 9-16, the second half of the complete Level 1 Student's Book.