What is the main controversy over the citizenship requirement for the presidency

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.

Why did trade along the silk road increase after it fell under mongol control? o people stopped using camels the mongols paved the road o it became safer to travel the mongols were better traders next question ask for

One of the main things that tobacco did for jamestown was to?