听力原文： The family is changing. In the past, grandparents, parents, and children used to live together, and they had an extended family. Sometimes two or more brothers with their wives and children were part of this large family group. But family structure is changing throughout the world. The nuclear family consists of only one father, one mother, and children. It is becoming the main family structure everywhere. The nuclear family offers women some advantages: they have freedom from their relatives, and the husband does not have all the power of the family. Studies show that in nuclear families, men and women usually make an equal number of decisions about family life. But wives usually have to 'pay' for the benefits of freedom and power. When women lived in extended families, sisters, grandparents, and aunts helped one another with housework and childcare. In addition, older women in a large family group had important position. Wives in nuclear families do not often enjoy this benefit, and they have another disadvantage, too women generally live longer than their husbands, so older women from nuclear families often have to live alone. Studies show that women are generally less satisfied with marriage than men are. In the past, men worked outside the home and women worked inside. Housework and childcare were a full-time job, and there was no time for anything else. Now women work outside and have more freedom than they did in the past, but they still have to do most of the housework. Women actually have two full-time jobs, and they have not much free time. Questions: 17. Who used to live together in an extended family? 18. What advantages does the nuclear family offer women? 19. What is another disadvantage of the nuclear family for women? 20. Many women are dissatisfied with marriage and the nuclear family because they______. (17)