题目内容：
Passage 2
Schooling in the United States is the responsibility of the individual state and local governments. Since there are 50 states, there are many different approaches to education. However, all states require students to attend school until they are at least 16 years old.
Almost 90% of American children attend public school, which is free. Some attend preschool, which is generally privately run. Children start elementary school when they are 5 years old and continue until they are 12. Junior high school lasts for three years and senior high school for another three years. Well-off families may send their children to private schools, which charge tuition.
Some public schools, particularly those in wealthy suburban neighborhoods, have modern computer equipment, well-stocked libraries and extensive recreation facilities. These schools offer many after-school activities. Students are encouraged to join sports teams, play in the school band, sing in the choir or join a chess club. Other public schools, however, are poorly equipped and offer few after-school activities. About 20% of American public schools are housed in buildings that are considered unsafe.
Americans lead other industrial nations in the percentage of the population who receive higher education. In high school, students take the Scholastic (学术的) Aptitude Test (SAT); universities admit students based on the
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