Best Review books for Chinese SAT II, Math L2

I’m taking the Chinese SAT next month, and I haven’t prepped at all. I am a native fluent speaker and I have 5-6 years of Chinese school education under my belt. I was looking through the Chinese SAT threads and everyone said that the curve is EXTREMELY harsh and that you can only get 1 question wrong to score 800. If anyone has taken the Chinese SAT and scored well, what resources/review books did you use? I’m freaking out right now.

Side note: I’m also taking the Math L2 SAT next June, but I’m currently in AP Calc AB. Is it worth to buy a review book, or is it safe to just go in blindly?