What major world event caused europe to enter a new era called the middle ages?

How was slavery in mesoamerica, africa, and the arab world similar? many enslaved people were forced to pledge loyalty to their owners. many enslaved people worked in exchange for protection from foreigners. many enslaved people were captured during war. many enslaved people taught and tutored children.

World war i brought increased immigration to the united states from which country? germany france italy mexico

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?