听力原文： Life in the twentieth century demands preparation. Today, all individuals in a c

ountry must have adequate schooling to prepare them for their work as well as for their responsibilities as citizens. With this in mind, national leaders everywhere are placing more emphasis on the education of the young.

There is no national school policy in the United States. Each of the fifty states makes its own rules and regulations for its school, but there are many similarities among the fifty school systems. In most states the children are required to attend school until they reach the age of eighteen. When they become six years old, children begin elementary school. After six years in elementary school, they go to junior high school and remain there for three years. The last three

years of their public school education are spent in senior high school, from which they graduate at the age of eighteen.

A great number of high school graduates continue their education in one of the many colleges or universities in the country. After four years they receive a bachelor's degree. Some continue studying for a master's degree and perhaps a doctor's degree.

Why do the people and the government in the United States work hard to give their children the best education available？

A．Because they will be future leaders.

B．Because they will be future teachers.

C．Because they will be future engineers.

D．Because they will be future citizen.