My picks: 1. How did life originate from non-life? 2. What truly exists at the center of the Earth? 3. What (if anything) is the next evolutionary step beyond humans?
What would you ask, and what made you choose those three?
2. was big bang actually a thing?
3. How does the life if exists look like in other galaxies?
2. Is quantum mechanics the fundamental physical reality, or is there something behind it?
3. Does P = NP?