The description of this set (book & CD) should state that you need another set of audio cds to be fully usuable. The CD in the set only has a few of the audio portions needed to complete the lessons. The CD is called "Self-Study Audio Level 2". The full set of audio needed for all the lessons is sold separately for a very high price and is called "Interchange Class Audio CDs 2 (Interchange Third Edition)". So, I purchased what I thought was a reasonably-priced set and now I find it is incomplete. I am a volunteer ESL tutor so really cannot afford to complete this set so I am very disappointed & feel deceived. Until I bought the book I had no idea that certain sections were not included in the cd. So, be warned that a portion of this book is unusable without the additional and very expensive CDs.
Updated: To update my review above, even without the CDs, this workbook is very good. I have been using the lessons for several months now and have found them to include a good variety of current topics that are used for discussion, grammar lessons, and writing assignments. My star-rating is now 4.5.