There has always been slavery inside Africa.
(Sadly slavery is still in Africa today.)
Europeans sold goods that the kingdoms wanted.
The kingdoms kept pushing further and further into the interior.
This created a continuous cycle.
Whites were sold into slavery in Africa also.
(They were captured from barbery pirates in North Africa.)
The answer would be B) the Roman Empire, since they were the ones who established it, and the mongols came after the silk roads construction, alexander the great lived before the silk road, and many local governments also encompasses the romana
The correct answer is:
An understanding of the number and size of leftover planetesimals in the early solar system.
The giant-impact hypothesis proposes that the Moon was created out of what was left of a collision between Earth and an astronomical body the size of Mars, around 4.5 billion years ago, in the Hadean eon. The heavy bombardment was a period when leftover planetesimals hit planets during the solar system's first hundred million years.
C) the court process can take a long time and be very expensive.