Answer:
The Nile River
Explanation:
Both Ancient Egypt and Nubia were built in the valley of the river Nile. Egypt was on the North, while Nubia was on the south, in thethe lower river.
The two civilizations had elaborate trade – Nubia would sell the luxurious like ivory, gold, and iron to ancient Egypt, while Egypt would trade the grain, papyrus, and linen.
Their main and fasted trade route went through the Nile river. The river allowed them to trade more goods via ships and be faster than by caravans.
