I think it is B, because that is my best guess!
Answer:
OB . It allowed their culture to breed camels and travel to visit other places.
Answer:
How invisible particles can be observed in outer space. ... We call this invisible mass dark matter since it cannot reflect light. Gravitational effects are only way we can detect its presence.
Answer:
The slaves sometimes followed the Northern Star which was in the constellation Big Bear(Big Dipper)
Explanation:
