Answer:
The Mexico–United States barrier is a series of vertical barriers along the Mexico–United States border aimed at preventing illegal crossings from Mexico into the United States.
The 1917 Russian Revolution was not, as many people suppose, one well organised event in which Tsar Nicholas II was overthrown and Lenin and the Bolsheviks took power. It was a series of events that took place during 1917, which entailed two separate revolutions in February and October (with a great deal of political wranglings inbetween), and which eventually plunged the country into Civil War before leading to the founding of the Communist State.
D. I believe because it all happened
North America and south America
Justinian 1 was the last great emperor.