Complete the text below with the correct prepositions. MCDONALD’S The first McDonald’s restaurant was opened _______

The first McDonald’s restaurant was opened by Dick and Mac McDonald in the 15th of May 1940. The best selling products in their restaurant were hamburgers. So the McDonald brothers thought of a way to produce hamburgers more quickly. This was introduced in 1948 and became known as the Speeded Service System. The first franchised McDonald’s restaurant was opened in 1953, and today you can find McDonald’s restaurants in more than 100 countries. The meats in the burgers vary in the culture of the country. Franchisees and future managers at McDonald’s restaurants are trained at Hamburger University, which is located in Oak Brook, a suburb in Chicago. McDonald\'s is also known by its sponsorship invidious international sport events.