Please help, it is 14 questions. Really easy, (but I dont get it)

What was the most important consequence of the large-scale ecological changes in africa two hundred thousand years ago?

Which of the following is a likely reason that someone today might decide to move from a city in the midwest to the south? a. the decline of manufacturing in the midwest b. the many high tech jobs available in the south c. urban overcrowding in the midwest d. higher housing costs in the south

What was one effect of the emancipation proclamation on african americans in the north?