The practice exercises in this workbook are great and would be a very helpful edition to the matching textbook.
There's one big problem though... there's no answer key!
Practice exercises are useless at least, and could even be harmful, without knowing whether or not your answers are correct. The publisher has a form on their website where you can request an answer key, but i have yet to hear of anyone receiving it from them who was not part of an educational institution. I submitted the form a long time ago and got no response whatsoever. Be warned!