when you select an a block of questions, you are given the option of using only questions you've never done, but you may also choose the "all questions" option or the "incorrect only". There's at least one other option. To answer your question, yes qbank remebers your question. You get to choose how you want each block to be set up from the database. Most people suggest doing randomized questions that you've never seen before in 30, 40, or 50 block questions. If you get through those, you might choose to work only on those you got wrong the first time.
