I'm thoroughly confused about the setup. I took the Princeton practice test last night, and it is so much different than the other CB tests I have taken (Kaplan Diagnostic and Gold Standard, plus AAMC 3R) that I wanted to check on a couple things about the testing itself. Are the questions presented one at a time, or are all the questions for a given passage given at the same time? Do you have buttons to move to the next page ('next' and 'back') or do you manually have to change the pages? Where is the timer?