If you are preparing for the preliminary contest, I think it is over to look at the questions and find out the knowledge loopholes. Don't work too hard.
Moreover, all his questions are for money, and there should be no free download place. My questions are all from classmates, teachers or online. These years should be comprehensive. If you want them, leave an email and I will send them to you.
In addition, which province are you from, how high and what level are you in this year? I have many other things here, such as e-books, courseware and so on. I'll send you one that suits you.