As soon as I saw this post, I had to reply. I actually went through that piece of garbage with sticky notes marking where they screwed up. I don't know who [if anyone] edited or reviewed it, but they should be ashamed of themselves. There are at least a dozen mistakes, many of which are not just 'grammatical errors' but are genuinely WRONG answers.
I suppose in some ways it's good to go through the book just to catch the mistakes, but if you're genuinely trying to learn the material I would avoid this book like the plague. The verbal sections were not as bad as the chem/bio sections. If I remember correctly [I no longer have it] I only found grammar or printing errors in the verbal sections.
Regardless, REI should be issuing a recall on this publication.