题目

E In 1939 two brothers, Mac and Dick McDonald, started a drive-in restaurant in San Bernadino, California. They carefully chose a busy corner for their location. They had run their own businesses for years, first a theater, then a barbecue (烤肉) restaurant, then another drive-in. But in their new operation, they offered a new, shortened menu: French fries, hamburgers, and sodas. To this small selection they added one new idea: quick service, no waiters or waitresses, and no tips. Their hamburgers sold for fifteen cents. Cheese was another four cents. Their French fries and hamburgers had a 当前我国发展中面临诸多挑战，请举出几例。