List the groups of settlers who came to pennsylvania

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.

What are new social classes emerged due to advancement in agriculture ?

Is the weather changing? consider the data of severe weather that includes tornadoes occurring throughout the u. s. over the last four years. compare the severe weather for the last three years. then compare the first three months of 2017 with that data. based on previous years, what might the prediction be for weather during 2017?