So they can keep track of their work
Happy new year to you too and hopefully 2021 is better year
the correct answer is D
it was related to the food supply
The early humans moved out Africa when the climatic condition in the region of East Africa Rift valley,where earliest stone tools were discovered became increasingly dry. Hunting as a source of food also became scarce as animals also spread out of the region. Subsequent strains in areas where they conquered led them to migrate further across the globe.
The black death had traveled through trade routes
