Family structure has changed dramatically over the last 50 years． The "Leave it to Beaver" family is no longer the standard， and several variations on family have been created． Nuclear Family The nuclear family is the traditional type of family structure． This family type consists of two parents and children． The nuclear family was long held in esteem by society as being the ideal in which to raise children． Children in nuclear families receive strength and stability from the two- parent structure and generally have more opportunities due to the financial ease of two adults． According to U．S． Census data， almost 70percent of children live in a nuclear family unit． Single Parent Family The single parent family consists of one parent raising one or more children on his own． The single parent family is the biggest change society has seen in terms of the changes in family structures． One in four children is born to a single mother． Single parent families are generally closeand find ways to work together to solve problems， such as dividing up household chores． When only one parent is at home， it may be a struggle to find childcare， as there is only one parent working， which limits income and opportunities in many cases． Extended Family The extended family structure consists of two or more adults who are related， either by blood or marriage， living in the same home． This family includes many relatives living together and working toward common goals， such as raising the children and keeping up with the household duties． Many extended families include cousins， aunts or uncles and grandparents living together． This type of family structure may form due to financial difficulties or because older relatives are unable to care for themselves alone． Extended families are becoming increasingly common all over the world． Childless Family While most people think of family as including children， there are couples who either cannot or choose not to have children． The childless family is sometimes the "forgotten family，" as it does not meet the traditional standards set by society． Childless families consist of a husband and wife living and working together． Many childless families take on the responsibility of pet ownership or have extensive contact with their nieces and nephews as a substitute for having their own children． 1． In what aspect do single parent families usually work together ？ A． eldercare B． finance C． housework D． tutoring 2． Which of the following belongs to the type of extended family？ A． Jack and Betty， who have been married for over 15 years， have two children namedDaniel and Chirstine． B． Jose and Maria live with their 3 children． They also live with their parents， an uncle and an aunt． C． Two years ago Darrel and Tanya got married． Before they got married Darrel had three sons and Tanya had a daughter． Now they all live together． D． Harry and his wife Jane have been married for six years． They have one daughter named Melissa． 3． What can be inferred from the text？ A． Nuclear families are most common in America． B． The "Leave it to Beaver" family used to be a family type． C． Childless families tend to live with their nieces and nephews． D． Extended families form to take care of the old．