You are a historian studying britain. you believe that a rise in the average british citizen's income between 1800 and 1850 can be linked to a rise in literacy. you have many sources of data from a town in britain covering that period. which four types of data would you study to investigate this theory?

Where did the term “iron curtain” originate? the warsaw pact used the term iron curtain as a code word for communism. in a 1946 speech, british prime minister winston churchill said an iron curtain had fallen across the continent of europe. while visiting western europe in 1946, u.s. president harry truman commented that the mountains there looked like iron curtains. russian general secretary joseph stalin instructed citizens of eastern europe to hang iron curtains over their windows to protect themselves from stray bullets.