It's also, of course, not exhaustive. I've tried to write questions that cover a broad range of possible SAT questions, but in no way can 20 questions (or 40, if you count the first drill too) encompass every kind of question that will be thrown your way. I'm trying to supplement, not supplant, the work you should be doing in the Blue Book to prepare for the SAT.
The answer key, as always, is linked from the end of the drill so that you can work through the drill without peeking, but you can also access it directly here.
Feel free to print, share, etc.