I believe Europe is the correct answer for this question.
The discovery of petroleum/oil most likely greatly affected the economies of many middle eastern countries.
Answer:
More jobs, Lower prices for raw materials and more variety of goods.
Answer:
The U.S. entered World War I because Germany embarked on a deadly gamble. Germany sank many American merchant ships around the British Isles which prompted the American entry into the war.
hope it helps :)
