What was the main economic activity of tribal people who first lived in the nile river valley? a) farming b)hunting animals c)domestication of animals d)trading

d. the right to establish a one-house legislature

on this day in 1913, henry ford installs the first moving assembly line for the mass production of an entire automobile. his innovation reduced the time it took to build a car from more than 12 hours to two hours and 30 minutes.