HI!
I am 99% sure cerebrum is your answer. Please tell me if I'm wrong.
Goo Day
Answer:
1. They keep casts to preserve the real fossils.
2. Maybe someone would steal a fossil and sell it on the dark web?
3. They keep casts to keep the real fossils in prime condition, by that I mean like undamaged.
Answer:
Habitat loss, uncontrolled hunting
Explanation: