Just finished online basics last week actually. It was mostly the same format as the block tests. All either multiple choice, true false, or select all that apply. Best advice I can give is to just pay close attention to the wording of the questions and read them all fully and carefully before answering, cause they will try to trip you up. I promise you have more than enough time to get it done, so take your time with it.
Also I'd suggest devoting a good chunk of study time to blocks 1-3. What I found is that I didn't have too much trouble with the questions derived from 4 and 5 just cause they were all pretty fresh in my mind at that point, but I was a little bit fuzzy on the earlier material. Might have just been me and your mileage may vary, but that was my experience.