the book is too much for GMAT CR.
i have the LSAT and the GMAT bibles. i read that book and did the entire CR section in OG11
and got 4 or 5 wrong.
all u need to do is clearly identify what the question is asking and clearly understand the structure of the stem. everything else is common sense. i think this is the only portion of the gmat that tests intelligence. everything else, such as RC is just a skill acquired over time.
You tried your best and you failed miserably. The lesson is 'never try'. -Homer Simpson