In a transitioning economy, what is a downside of rapid economic growth?

Which of the following is an example of the pull factor known as economic migration? a. better educational opportunities pulling people towards a new country b. mexican laborers entering the us to work in agricultural jobs c. joining family members that are already in a new country d. crop failures driving people away from their country i am unsure on this question, i was thinking b? but i could be wrong.

The map shows information about river valley civilizations. which feature of this map best the reader determine the distance between two places?

What happened 10 million years ago? if u answer, u get 50 ! plz answer ; -;