题目内容：
Passage 1By now, people.s definition of what makes a family has changed. In a 1989 poll sponsored by the Massachusetts Mutual Insurance Company, three-quarters of the people rejected traditional definitions based on two parents and their children living together. Instead, they defined a family as "a group of people who love and care for one another". This changing attitude was reflected in American society, where families were extremely varied.
Ten times more adults lived alone in 1990 than had in 1900. Though most people still married, more couples chose not to have children. Many more marriages ended in divorce, leaving many families headed by a single parent. Some parents never married, and the stigma attached to children born "out of wedlock (已婚状态)" had almost disappeared. There were blended families, formed when two single parents remarried and together raised children from earlier marriages. There were families in which the partners were homosexuals. There were also more marriages between partners of different races.
The physical surroundings of families have changed as well. In 1900, 60 percent of all Americans lived in rural areas. By the end of the century, 75 percent lived in cities and suburbs. Homes have changed, too. The average single-family home built toward the end of the century had at least two stories, three bedrooms, two and a half bathrooms and a garage
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