NCLEX PN Question

For those who have taken the NCLEX-PN, how much of a focus was there on Acid-Base balances & ABGs on your individual exams? Also, if you did get questions r/t this, do you have any words of wisdom on an easy way to study for it?

Myself and a couple classmates are reviewing for the NCLEX-PN & this is one area that was not discussed in our nursing program. The instructor told our class that they do not teach it until 3rd semester of the RN program because it is such a difficult concept to grasp. So my classmates & I are hoping that none of us will get thrown a question regarding this topic, but at the same time, we're trying to become as knowledgeable about it as we can.

Thanks, ahead of time, for any replies or input.