Answer:A
Explanation:I know it is convection it's the only one that even makes sense.
Gladiators fight other gladiators
1. Valentina Tereshkova
2. 48 orbits
3. maybe 7000 years
4.manufacturing steel
5. horizontal?
Watchdog function is the answer i believe
I think that the answer is A. B,C, and D are very innate reasons for the proficiency of the mating.