How many years are there in between 1872 and 2011?

What were two reasons why it was so dangerous for merchants to travel during the middle ages? What person is the most responsible for bringing an end to the Cold War? What did the Romans borrow from the Greeks? What is the concordat of worms 1122? what century was 1899? How did people live in the 1060s? Beginning in Eurasia two early innovations had a huge impact on agricultural societies. They allowed people to produce surplus food and in turn populations grew in size. What were the two innovations? What rituals and traditions did medieval women have? What did the ancient greek and roman government and the English government contribute to American government? What is the difference between traditional? What event caused the patricians to change the Roman government? What seas touched the Roman empire? What is a manor and who owns it? What are the 5 most significant reforms that Octavian Augustus made during his reign? What were some medieval servants jobs? Did at the height of the empire Rome's system of roads reached a total length of 10000 miles? When did the modern history begin and end? What are some pros and cons of the roman republic? Does 1600s mean 16th century? Is Richard arkwright a bad man?

How many years are there in between 1872 and 2011?