I. 阅读理解(每小题2分，共30分）
A
In 1955, a man named Raymond Kroc with two brothers named McDonald opened a popular restaurant, McDonald's, in California which sold food that was easy to prepare and serve quickly. Today it is one of the most famous and su ccessful"fast-food" in America and the world.
Why was his idea so successful? Probably the most important reason was that his timing was right. In the 1950s, most married women stayed home to keep house and take care of their children. In the 1960s, many women came back to the factories. This meant that they had less time to do housework and preparation of meals, so they depended more on fast-food restaurants. Single parents also had little time to spend in the kitchen. People liv ing alone also depended on this kind of food, since cooking for one was often more trouble than it was worth.
From the success of Raymond Kroc' s fast-food business, we can say that social economictrends（社会经济趋势） influence where and what we eat.
( )1. "Cooking for one is more trouble than it is worth" means
A. cooking for several people is worth more money
B. it is not necessary to take much time to cook for one person
C. there are more problems when one person cooks
D. there is a lot of housework and preparation to do when one person cooks
